Yes, do it all the time.
Solution to all problems noted so far is:
Get metal pipe just large enough to slip over post.
Cut pipe length so that when bottom end hits ground T post is driven to exact depth you want.
Pipe length prevents catastrophic bends in post.
Cap end of pipe so it is now a post driver. Weld or screw cap end on pipe.
Use flat of bucket, centered, to pressure post+pipe into ground.
Go slow, raise FEL every few inches to reposition pressure point and keep post reasonably straight. Keep FEL bottom almost flat.
Need ground person to position post+pipe. Have them hold just to get it started then back off.
Watch carefully. When a rock is hit, front wheels WILL start to come off ground. STOP immediately.
Drive post until pipe end touches ground. Move to next post.
Sometimes hard ground/small rocks can be penetrated by briefly tapping top of driver with FEL. Try it. if it works, continue, else live with it or move post.
Good luck...this is absolutely easiest/cheapest way to drive posts. Small investment, big returns.