The way i had it broke down was each card face was the lvl..so 2 of diamonds(lvl20), 3-9 od coins 30-90, and last 3 were NM types Cardian. The higher a Manuister went up the longer the Cardian would take to be summoned, the lower the faster. Each Cardian had specific durations, meaning a minister needs to keep crafting new ones repeateadly. Think casting a tier IV nuke.
As far as numbers the closed the Cardian matched the maniuster lvl, the less a mainster could have left out. For example, if lvl 90 a Manister could have only 1 lvl "9 of coins"(this matches current pet jobs functioning) but this same lvl90 MNT, could concieveably have out 2 -"8's", 3- "7's", or 4-"6"'s, cap would be 5-"5's".
With the play between card types (RDM, wAR, etc) and mixing a match a Manuister could be a one man army. I didn't have any "Hard" number just general ideas.

As far as the "casting/crafting" times, the lower the card face the faster the speed. Think tier 1-4 spells. Obviously SE would have to make Cardian cards stackable and tradable. If SE wanted to add more balance, I supposed some sort of MP formula could also be added to the mix.

The very large drop in the players own melee damage due to "crafting" should be offset by a more higher than normal strength in the cards themselves. Obvious "5 of coins/lvl50" fight lvl 80-99 mobs would be useless otherwise. So I suggest a cheat or go around, that no matter what lvl cards they have a standard hit damage/accuracy that allows them near perfect level, though their "bodies" (HP/DEF/MP) would be lvl appropriately weak.