You never want to comp all stat x. Depending on if you're a cat or a raccoon also factors and if you're pure/hybrid. Primas need more AP (Two Hit, and you prob don't want to go pure HP Prima anyway), raccoons either pure or hybrid probably want more HV (iirc HV > AP because less Full House recoil for pure). I try to keep my Diva around 30k HP and AT LEAST 300 HV (which is a general rule of thumb, anyway) and just get AP from refining my weapon. I'd say as a higher level charm you want to stray away from compounding AP. For a Prima you'd want more AP for 2 Hit Combo. Hybrids can pretty much go anywhere (HP/AP/HV), but I prefer HV because we have a buff for it, so it's easier to get in mass quantities.
You won't really know what to compound with what until you know what you need to aim for. I've made like, 3 different Jen Belt's. First AP, then decided I needed more HP, then decided I had too much and made an HV belt.