Okay bear with me here. We know you can BS Attack into CC with a -6 modifier for each friendly unit engaged in the CC and if you fail your Attack by the difference of that modifier the attack hits your own unit. Now if you were to miss said Forward Observe BS attack inside there your unit would then become Targeted as "and instead of forcing the target to make an ARM Roll, forces him to enter the Targeted state." Since Targeted gives a +3 to BS and Hacking Attacks against the Targeted Unit, would that change the -6 modifier for firing into CC to a -3? (I know it wouldn't, but the thought that floated into my head was too silly to not share)
You could combine Targeted, MMX, and Fireteam bonuses to get a Crane rank to BS21 (BS12, +6 MMX, -6 Engaged, +3 Range, +3 Fireteam, +3 targeted) so there's no chance of hitting your own trooper. Grunts can get to BS20, still enough to be safe.
MMLX isn't a BS Attack anymore, (the first bullet on the Wiki right now is not in 3O or the latest Rules PDF. DMs with IJW seem to indicate it was from a pre-print version.) so the Fireteam bonuses and Targeted won't factor in sadly. Still a great tool for the situation though.
I thought that you make a BS Attack as part of MMX, but it doesn't count as a BS Attack in and of itself. Essentially, why is it different to Spec Fire? (which is also not a BS Attack tagged skill)
The difference is that Speculative Fire has this line in its effects: The user may make a single BS Attack against a target outside his LoF. So using Speculative Fire allows you to make a BS Attack and since you are now doing that, the modifiers come into play. Marksmanship LX does not have an equivalent line. It could be argued that the first bullet under Requirements ("The user may only benefit from this Special Skill when he declares a BS Attack.") would work similarly, but that line only exists on the Wiki and not in the other 2 current rules locations (most recent PDF and 3rdOffensive). That specific line was in the requirements for the old version of MMLX. I DM's IJW about the discrepancy and he said it was in his pre-print version of 3O, so it is likely that it was a mistake and dropped intentionally as it kind of breaks things with MMLX being a skill of it's own.
It is worth noting for consistency's sake that Triangulated has a similar wording to Spec Fire. "Allows the user to declare a BS Attack with one of his BS Weapons..."
Just because it's not a BS Attack label doesn't mean it doesn't produce a BS Attack. (Also, Crane is the dude with Heavy Armour, you're thinking about the Pheasant sniper)
Even if you Forward Obvserve into melee, and then succeed, that gives you a +3 MOD to hit, but it doesn’t change the fact that if you miss by 6 you hit a friendly trooper. If the trooper fails his Roll and the Failure Category (FC) is less than or equal to the MOD applied for allied troopers (-6, -12, etc., depending on the number of allies in that CC), then an ally takes the hit and is forced to make an ARM/BTS Roll. If several allies were participating in the CC, the attacker can choose which one takes the hit. That rules doesn’t care what the final modifier to the roll was. It only cares what the modifier applied by the “BS Attacks Into Close Combat” rule was. For that matter, even if you arrange a situation where you ignore any Modifiers to the roll, those rules only care about your failure category being equal to the modifier that you ignored.
Well, if it's not a BS Attack, even if strongly implied in the effects, then what else breaks? Does it not have a range band? Can it even deal damage? Can it be dodged? In either case, I think the question in the OP can be answered with that a failure category isn't a MOD as such, which means it gets silly when you try to shoot a TAG surrounded by 4 of your friendlies.
MMS LX is the only Entire Order Skill that is nested into BS Attack instead of the other way around. MARKSMANSHIP LEVEL X ENTIRE ORDER Attack, Optional REQUIREMENTS The user may only benefit from this Special Skill when he declares a BS Attack. This Special Skill is only usable in Active Turn. The user must be using a BS Weapon with a B value of 2 or more on its profile. There are multiple reasons why the rules aren't made to cover this as you can technically declare MMS LX as part of a short Skill BS Attack. Unlike Speculative Fire or Triangulated Fire you don't declare the Skill Marksmanship LX, you declare the Short Skill BS Attack and then activate MMS LX as a part of it. RAW the Entire Order tag for MMS LX does nothing. Now this is clearly not intended as we all know how the old MMS LX worked. But as it stands a shot using MMS LX is most certainly a BS Attack. While not included as a label in MMS LX, you have to declare BS Attack to use it to begin with.
This is so weird on many levels... 1. So I can end up targeting my own guy? 2. So, is MMLX useless again, or does it benefit from +3 BS for a link? Coffee talk time for this edge case it seems...
It's a bit of a mess, the first bullet point in requirements isn't there in PDF or book or something, and which version is correct is not entirely clear. In either case, it's fairly safe to say it's a BS Attack as far as mechanics are concerned, because otherwise... errr... Just not so clear as far as coordinated is concerned.
We've done this before. The skills with the BS Attack trait are all "BS Attacks". MMLX let's you perform one of those skills. MMLX is part of a family of skills that allow you to perform BS Attacks as nested skills, but aren't (with one exception*) themselves BS Attacks. All the normal MODs that would apply to a BS Attack if it was declared on its own apply to a BS Attack declared as part of MMLX. * And this exception is probably a mistake.
The problem is right now that the first bullet point you have highlighted is only on the Wiki, it was not on either print version (counting the PDF as print) of the rule. I have mentioned this to @ijw and he was surprised that it wasn't in the printed version of 3O as his pre-print copy had that line. So relying on that is dubious until it is confirmed to be correct. The changes allowing it to ignore cover for both BS and ARM mods is already a huge upgrade. Then you add in the clarification for Saturation Zones...
No it doesn't. At best it allows you to declare the Entire Order while declaring the short order BS Attack (ignoring how that makes things odd on its own), that isn't the same as the wording in both Triangulated and Spec which both "Allow" you to declare a BS attack.
It is also worth noting that the first bullet point is a word for word hold over from the previous version of MMLX, which wasn't a Short Skill or Entire Order, but an Automatic Skill so would have needed that to allow it's use. Don't get me wrong. I would love for it to be able to be declared in a Coord Order with other BS attacks, but the discussion that was had when the rule was first revelaed decided that wasn't the case, specifically because of the lack of that first bullet in the PDF (which was all that was available at the time) https://forum.corvusbelli.com/threads/new-marksmanship-lx.26080/
I get how it's written, but it's written really badly given how it now works. To paraphrase: "You declare a Short Skill that allows you to benefit from an Entire Order skill." MMLX only makes sense if you play it as belonging to the same family of skills as Lean Out and Spec Fire. Understood like that it's clear.