Yeah that's definitely not how a tank should handle.
Ill be releasing tank game soon to arcade, be sure to check that out to give you a feel of it.(Global Tanks 2D)
But yeah your movement should be smooth and it's a tank probably should be slower, but fix the movement first. Not sure how to fix it but I know that I used Car behaviours rather than 8 movement.
thanks for the suggestion i switched the 8 direction with car behaviour and changed the origin point on tank it really improved movement of the tank.
and also decreased speed of tank