Subcontracting HVAC installs turning into a crap-show

I've been subcontracting out some of my ductwork jobs to a couple guys I know, but lately it's been nothing but headaches with delays and shoddy installs that I'm left cleaning up. We're in Texas so the heat season hits hard and clients don't wait around for excuses, had one project where the sub botched the R-410A lineset on a Carrier unit and I had to redo it myself last week. TBH, I'm frustrated as hell thinking about dropping them but finding reliable subs for zone 2 installs around here is tough. Anyone else dealing with this in the growth phase? The paperwork alone is killing me on these referrals-turned-nightmares. Might just stick to solo work for a bit.