I've hooked on to the center of the axle plenty of times with no issues. Depends...are you stuck in mud up to the running boards, or just flat towing a few blocks to get home on a paved road. Then, it has a big effect on who is doin the towing.
for example, my friend who has a C Allis tractor with a loader on front, got stuck in a snow bank, and had the wife pull him out with the pickup. They hooked up a chain, with plenty of slack, she thought it best to floor it to make sure it was a success, ripped all the ears off the block where it connects to the rest of the tractor. He said, one minute he was sittin on his tractor, the next minute, after the big bang he was lookin at the ground! Moral of the story, hook on the center to move the thing. have a qualified operator doing the towing and you will not have a problem. done it many times myself