They get the 1K units - which can handle FT rushes. (Mobi's come to mind)
Plus being an engie is cool - because of all the credit you make repairing/fending off rushes.

The sweet thing is when you capture an enemy APV and run back to their base and hotwire the OBI/HoN --- big suprise -- i've been in a couple of "WTF?" games when your buildings start to blow while your thinking the game is in hand. (Thank you very much Zukkov/Danzigger for that one- LOL)

So - BD is the best thing to do i guess...