I agree it looks interesting and could be made work with C&C ancients with a little modification.
The first would be to assign each general named on the cards a command rating between 4 and 6 for hand size.
After that would be what the units on the cards are in ancients terms 1 unit on card is 1 four block unit should work well as it leaves largest army would be 19 units smallest starting army possible is 12 units with Caesar and 3 2 unit cards.
Bd= heavy infantry (Julian/Marian legion rules)
Bd(I)= medium infantry(Julian/Marian legion rules
aux= auxiliary infantry
cav =medium cavalry
lh= light cavalry
El= elephants
wb= warriors
Ps= light infantry
Kn= heavy cavalry
Sp= medium infantry (no ranged)
Pk=heavy infantry (no ranged)
Hd=auxiliary infantry which don't hit on sword
For each card with a generals name 1 general piece.
If no card with a general is played take 1 general with command 4
Next is generating terrain maybe roll a d6 for the number of terrain pieces on the field with 5 and 6 counting a zero a lot of battles have none.
Possible pieces
woods 3-5 hexes
river fordable across the board
marsh 2-4 hexes
hill 2-5 hexes
camp hex (defender places)
ramparts/field works 2 hexes (defender places)
broken ground 2-3 hexes
coast running along a board edge
roll 2d6 to determine the terrain
2 Marsh
3 Marsh
4 coast max 1 edge if rolled again re roll
5 camp
6 woods
7 hills
8 river max 1 if rolled again re roll
9 broken ground
10 rampart
11 hill
12 woods
After the number and types of terrain are generated the defender places all camps and ramparts
if none are rolled the defender places 1 piece of terrain on the board followed by the attacker placing one piece (the player placing decides the number of hexes) alternating until all terrain is deployed.
If camps or ramparts were placed the attacker places the piece after them.
Next up are the rules for losses if the same card is played 2 battles in a row.
Carrying forward losses as suggested could result in the campaign being one sided after the first battle. Maybe if the unit was reduced to half strength or below starts the next battle with 1 block less if not starts at full strength.
but the key feature of interest to me is the nature of drawing cards to generate the battles. this is a cool mechanic I think:
If you like that idea you should check out piquet theatre of war campaign system it uses cards for everything I have played in campaigns using this but with the battles fought using overlord memoir 44 or battlecry using a modified version for 8 players.
Theatre of war is a detailed but complicated system never umpired a campaign with it only played in them.