Maintanance is high with leopards too, it is an excuse that only the US has maintanance intensive MBTs. The only difference really is the increased logistical effort for high fuel consumption of more specialized fuel.

Training, maintanance, ammo logistics are all comparable otherwise. And if engines (where the only increased maintanance complexity for abrams would be justified) are that heavily damaged it needs to be shipped to poland for repairs anyway. But thats no different for leos. Ukrainians will be trained for operating them in the short, not for having crews being able to maintain every possible failure or damage under battlefield conditions.

And it is not like the US wasn't able to provide tanks and fuel over this distance. They did it in the middle east too and now would need to provide the same but with way less tanks and even without their own personnel except some maintanance staff and supply staff in poland.