Can I use Mercon V, Dex/Merc, Dexron VI fully sythetic for a wc t-5 transmission?

I just put trans back into car the other day after an engine rebuild and it dumped a little fluid plus the seal used to leak.

I thought I was a quart low so I bought valvoline dexron VI synthetic, then had a half quart of dex/merc at home I threw in too but still is low. I have mercon V also but now that I already used two different types and one was sythetic im wondering if these are all compatible?