OPs querstion was how to counter that list thats how I answered and it doesn't have to be a TAG HIs also work, we simply don't have much AP
Which is not true, saw somewhere post of IJW wartrader, who explained that symbiomate is more like a one use courage. + in rule of guts roll is written about surviving attacks "or that do not provoke ARM or BTS Rolls." (from infinity wiki) AD is not always so good vs Tohaa, because those triads from a good player can cover all possible flank approaches. Played Tohaa a lot. Won few tourneys. Most scary stuff are supprise shots (and other with negative mods attacks), mines, enemy high BS and templates from camo\hidden, which can get whole triade. NCA is powerful. Played once vs 20 orders Neoterra with 3 hexas, locust markmasnship rifle, fusilers link and two auxillers. Won mostly by luck. NCA has so much of cheap pushing, cheap and effective ARO, I really don't think tohaa can hurt it so much, always a brain-burning when playing against good NCA. When someone take off my symbiomate from my pushers (gao-raels, neema, ectors, sukeuls) Im not so brave anymore. That symbiomate is a one order advantage. And when its lost, tohaa is left with a mediocore BS, low armor.
Can be bloody effective. Paralyze with mine weaker member of triad. Tohaa will spend time on some painful thinking if he needs to relink and leave that guy behind or to somehowe diffuse the mine from far-away distance. From the other side tohaa has some very effective diffuse guy - symbio beasts, and holoecho kotails (but those are rare). But still...a good placed mine near link, will bring tohaa some trouble.
If you mean this thread https://forum.corvusbelli.com/threads/do-symbiomates-prevent-guts-completely.568/ IJW commented once, and we took the English language and the direct Spanish translation apart and arrived at a, "no, it's not Courage". If you consider Marksmanrifle Locusts and Hexas NCA powehouses we probably have very different opinions about NCA. Especially the Surprise Shot thing has me scratching my head, no one is better than Tohaa at soaking one boosted BS Attack with a Symbioarmour/mate. I'd agree with you that NCA is a bad matchup for Tohaa though - as far as those exist, take it with a grain of salt. Personally I dislike some factions for internal bullshit like Mutts, but it is always the player that gives me reason to expect trouble. My usual opponent would very likely give me more trouble playing MRRF than the average opponent would when playing Tohaa. Personally I play as much against Aleph and Tohaa combined as against everything else, so I'd expect to make less errors and be better prepared against them. People tend to forget about Symbioarmour effectively granting two wounds (or more) and how that affects armour value. When comparing a Sukeul to a similarily priced Nisse, the Sukeul gets more value per point, not to mention a failsaife against crits. A Mate also is a failsafe against the harsh reality for most troops in Infinity - lose a FTF and you might as well die. Tohaa play by their own rules, the mere fact that a perfectly intakt troop that merely lost a Mate can be considered "vulnerable" shows that. Tohaa BS being bad is also a myth, any of their gunners has either a MOD, Visor and/or easy access to Link boni to make up for that. On top of that readily available Eclipse Smoke to cheat bad firelanes or other Triad Members to stay in favourable Rangebands or circumvent BS entirely by using CC or DTWs. Additionally Tohaa top range gunfighters are all very affordable and can be taken in numbers for redundancy. Haqq, Nomads, Ariadna and some sectorials like Morats are just as bad or worse in a slugfest.
Thats possibily a result of Symbiont Armor being somewhat underpriced. But either way, Sukeuls are contenders for the most useful models in the game. Good weapon options, specialists, can be in triads, 2 wounds, mimetism, cheap.... yeah, you can't really want more out of it.