Ukrainians Demanding Tanks

The Ukrainians are demanding tanks well demand is the wrong word but asking strongly to receive tanks. I think there are concerns about ammo supplies for those tanks and the barrels for those tanks so they want to move to Western tanks tank models. There's concerns about giving them M1 Abrams tanks because they're very difficult to operate heavy and so forth. Could that enable some sort of breakthroughs on these entrenched defensive lines that's a thorny question.