Might be, but I am unsure on their anti-tank capabilities. There machine guns won't do too much. 50mm might work on some tanks, but not all, plus it be a short barrel without much velocity. Chain gun would be ruled out even if the bots are allowed.
They wouldn't have advantages in the rural terrain that is normally faced in tankery, and would probably be disadvantaged. Tachikomas seem more geared to an urban environment, especially with lots of structures such as high rises.
Might be, but I am unsure on their anti-tank capabilities. There machine guns won't do too much. 50mm might work on some tanks, but not all, plus it be a short barrel without much velocity. Chain gun would be ruled out even if the bots are allowed.
Keep in mind that the Tachikoma's bazooka fires a shaped charge, which all WW2 tanks are highly vulnerable to. Think about how the Panzerfaust was so deadly to tanks despite being so small.
The Tachikoma probably would have to be given regulation ammo, though. Even so, with its extremely high mobility, it wouldn't have any trouble getting behind a tank, or it could jump over it and blast its shot straight down onto the roof. Not even the Maus could take that.