I've never seen someone use straps to secure a tractor. We have always used 4, 16ft, 3/8" chains with 4 binders to secure our tractors when transporting them across the state.
Haha! I had a strap at all 4 wheels, it was the strap tails that made it look crazy. I've had the tails come loose on me before and start blowing everywhere so I make sure they stay tied up! Lol