Restructuring of Engineer Points

We need to do something about the number of sentinels etc players can spawn.
At the moment, players are limited to a max of 3 turrets, 2 vehicles and 1 building. Each type has it's own points - turret points, vehicle points, and building points.

How about limiting players to a max of 1 sentinel, 1 turret, 1 vehicle and 1 building, and having combined points?

So for example you had say 20 points you could spend on what you liked. So you could buy 1 good turret. Or you could buy a not-so-good turret and a not-so-good vehicle. But not 2 not-so-good turrets.

Would make the whole system simpler.
(There is a separate question about if adrenaline should be used - but that is separate)

That might limit the class's support role too much, unless we're considering removing a lot of summoning for others.

However, I like the idea of combining things into one point value. That would also help in reducing the levels needed to max out the class.

I wonder if there's a way to do some neat thing that would make it look like a "thing" is being built? Put some delay in, say, a tank just popping up from no where? Or have the tank "there", just cover it with a skin of some sort that indicates it's "being built" but keep it locked until done.