How about this - they add the vehicles in as a support to the ground battles we already have. It could have a similar mechanic to the At-At or Orbital Bombardment from the TB's or the capital ship from ship battles. You can choose one vehicle per battle and they each behave differently.
At-Ats are slow, devastating AOE attacks.
Speeder bikes are fast, single target attacks.
Sandcrawler has no attacks but gives bonuses to droids and jawas.
Sand barge gives bonuses to scoundrels.
Snow speeder has innaccurate AOE or heavy damage to a single target.
You could have to collect shards and level them just like characters. It could work!
-Z