Maybe the main benefit is psychological. Ukrainians will have more confidence, the Russians less. A lot will depend on which tanks get knocked out first.

NATO needs to send tank mechanics to Ukraine.

It sounds like the Abrams requires a lot more effort than the Leopard to put into battle.

Canada is sending four Leopards to Ukraine. Critics think that is too low. But Canada mothballed its tank fleet about five years ago as it deemed tanks are no longer necessary in Canada's military. So the four tanks might be a sign of what tank are really ready for battle. More may be coming later.