I do think there may be too many vehicles for a 40v40 version. The number of vehicles was fine when the battles were 80v80 or more, but not sure it works for the bg version.
I suggested in the Epic Battleground Feedback thread that a possible change could be to reduce the number of vehicles you get per battlefield workshops to 3 (down from 4) and 2 for keep workshops. This means the most vehicles a defending team could have would be 16, down from 24. Offense could only ever have 12, down from 16.
I think that would make it much less vehicle focused - I don’t think Wintergrasp should ever have more than half a team be a vehicle.
I’d also tone down the damage vehicles do, but buff their health to make them more tank like.