If you have random cards to drive play like D-Day I can give you an idea:
Rocket Artillery, gets to roll 3 Dice
Snipers, Casulties cannot Return Fire
Reconnaisiance Vehicles, If the unit wins in a combat territory it can move again in equivelant NCM
Tank Hunters, Can Target Armor
Assault Battalion, When Fighting in City Zones they roll 2 Dice
just some ideas... But they are played like Tactics with a Twist... Each player gets a seperate list of Specialty units equivelant to the amount of Order Cards... When a new order comes into play so is a new specialty unit... You can activate it if you choose... You can hold it in your hand as long as you like with a limit of 2 cards... when played the unit effects only the amount of units or battle limits allowed per what the card says...
Its funny cause I got on right now to research Market-Garden for the possibility of converting it into a "Battle Game"...