(there'll be guides and more info in time)
Idiot guides please. :D
When it comes to PvP the focus will be that players with a certain rarity face those with a similar rarity to make things even.
I think it is good to have a match-maker system where possible, to stop domination.
Keep in mind however that alpha cards will be scarce, the ones that get minted from alpha vials will be all that will ever exist. Thus don't waste them on "any" wild creatures if you suspect they have low stats, or save them to attempt to capture radiant wild creatures.
This is good to know!