Kosuil with Nema could be handy, in case she get imm-2 by e/m or hacking (e/m is not rare now). Draal is more of a toolbox. Kriigel with smoke is a must if you want to use the tagma msv as active turn shooter. From what i've seen till now Spiral offers many solutions. Can't say the same about all new sectorials.
Kumotail Bioengineers are cheaper and are capable (WIP14) doctors in addition to being an engineer. Consequently they are better fit to keep Neema up and fighting. In case you want a firefight, you already have a decent fighter (Neema) in the fireteam. Right tool for the right task. Meinetwegens adding a subpar fighter to the fireteam is less important than doctoring.
I have used the Kosuil in most of my lists in Tohaa since the unit was introduced. It's a durable Triad button pusher and one of the better options for Symbiobombs with its 14 WIP. Keep in mind that the 25 point profile is a minelayer and not an engineer, so no button pushing for that option. I have found that both the BSG Panzerfaust and the K1 Combi can be dangerous. I used the K1 Combi with an assist from a Chaksa HFT to take out an Avatar one time.
The Kumotail is to squishy when I play her. And the K1 Kosuil has killed many hard targets for me. Never had success with the Boarding Shotgun cause most of the time he was only an order monkey and I only benefited from his symbiont armor.
Mostly as distraction and roadblock Let the opponent waste orders on discovering them whenever possible and don't reveal too early excpet for free or very favourable shots. After that take shots at whatever possible, they likely don't survive the 1 turn.
