If we are talking Hassassin Bahram, they are probably the best choice for an offensive core fireteam in the sectorial. They are bristling with weaponry and are effective in a wide variety of range bands, situations and missions. 0 SWC Panzerfausts, D-Charges and D.E.P.s everywhere, X-visor on the spitfire and Heavy Rocket Launcher, Smoke, Minelayers, a Haris option, an e/mauler, shotguns everywhere, specialists... The list of what they can be sent to do is shorter than the list of what they can't be put to task on. Not to mention they all come with Number 2 built in which makes for a fireteam that is very difficult to break. If we are talking about vanilla, I can understand the sentiment much better. A mine layer here or a smoke grenade launcher there are nothing to sneer at, but I wouldn't be putting Muyibs on the board to either rambo about or just defend camp. There are also better specialists in this case. Some people do like taking the smoke launcher as lieutenant to get that extra smoke in later turns though. Your milage may vary. A midfield minelayer or two (AVA3 in Bahram) is great for dealing with warbands and other fast elements that are racing down the field to box you into your side of the table. Though the Forward Observer profile has to compete with Hunzakuts, Al Hawwa and Tuareg in Vanilla, they are your only infiltrating marker state specialists in HB (except technically Yasbir but he can't holoprojector lvl1 as anything realistic outside of the deployment zone).
The advantage of the Swiss being that it is roughly the same in offensive power against a target in cover (hitting on 15s) but is much, more tougher. An additional -3, an opponent is more likely to dodge, and ARM 5 with 2 W. Seriously, half the time? It's the ARM 5 on a S2 mini that's the real pain in the arse. Whack that thing with a MSR DA round and watch it bounce both shots often enough!
Swiss are also almost 2x as expensive as a Spetz. I'd expect them to be better. I personally love the spetz and the swiss, but I'd take 2x Spetz over 1x Swiss everytime. Good thing they're in separate factions.