You may be right about it being rougher in the US. I did not hesitate to use some occasional Tae-Kwon-do or combat Judo when needed.
Ah....The Joy of Hitting....miss it.....
Yeah, I played in a pickup match against some US navy sailors back in the late 1970s.
The first half they were destroying us, by slamming us so hard in tackles. The second half, we regained our own because they had now become much more cautious as they realised how much that hurt.