This is for future games and not for WZFF (minus the soldiers and Knights)
Crawlers: keep them the way they are but have a pack leader (like the leaked image), something that acts like the Shamans from SWTFU but without the teleportation or make the pack leader the thing you have to kill all of the crawlers that he controls.
Knights: ok let’s get WZFF out of the way. Reduce the amount of Knights that spawn and make them incineration canon happy. Ok now for future games. Make them spawn Warchers like they used but that is also their weakness since they always open their face wich is a one shot one kill and give them that cool teleportation attack they ised in h4.
Watchers: Just make them like they were in h4 only without the whole revive bs.
Vehicle: now that we have a promethium flying vehicle let have like a ghost/gungoose type thing.
Other: have with more variety. Use the created story arc to your advantage