Which Orc hero do you prefer?

Yes, I would definitely do that. I generally like ranged armies, and I use these weak ranged units for their intended purpose... But that's off-topic.
However, rushing with Tilshek is quite possible; you just need to invest in the ballista. Of course, every fan of machinists knows that.
Krag is truly a beast. Especially with a good Attack skill, Stun, and Devil's Strike, and Support.