basic method is to send vespids with kroot at same time to kill builders and prevent vespid targeting and decaps take a kill of gen then take leave hopefully he makes gen inwhich you sell kroot and go Hero+flamer and finnish pop with firewarrior
4 stealth cap don't build close to cron base
2x kroot+ vesp is normally all you need 2x firewarrior+ commander can delay warrior mass efftivley for you to get transport+ drones
just don't lose vesp's you need req to keep kroot @ 4-5 members at most