Enough so they can be killed/beaten by the boatload, but not enough that they can just swarm the Autobots and butcher them with superior numbers of say...fliers.

You know, just send 50-60 fliers out after the 'bots and rain blazing death from the sky so fiercely there's no way they could withstand it?

Instead we see 6 to 8 on average at any one time.

I dunno, it's tough to reconcile sometimes.

- Coeloptera

 

no i think megatron just has the surviving clones scoop up the parts of the dead ones, and puts them back together, then sends them back out again.  

in other words, recycled cons!