Marcus and his crew are quite low Wp. Obeys work wonders, as do Lures to force them out of position. Manipulative/Terrifying really messes with the many attacks his crew wants to get off as well.
Against Mei Feng you want anti-armour. Pretty much her entire crew is reliant on it to survive. Bringing Aeslin or whatever to eat Scrap Markers helps cut down on her Railwalking a lot, as well as helping scheme
Hoffman is much the same as Mei; take anti-armour. I've not played him much, but his crew feels really slow, and not super efficient scheme wise
Ironsides is relatively slow and not heavy on the schemes, outisde of the Miners. If you can Lure her models out of position, or otherwise run circles around her with faster models and movement tricks, she'll really struggle. Stitched also really mess with her, thanks to Gamble.
Colette is a tricky one, but models that counterscheme are your best option. Iggy works best, and I could see a case made for Aeslin/Grootslang, since they can't be Distracted.
Sandeep is one I've had really no struggle against so far, The Carver wrecks him. Pile on the pressure and don't let his summons grind you out of the game