Is a W/mo good at tanking mesmers,eles.
Or is a W/e the better choice.

A rather broad question. Really depends on the type of W/Mo / W/E and the type of Mesmer/Elementalist.

an anti-warrior Mesmer or Ele will always kill a Warrior, but if you want to tank get a W/Mo, W/E is more for attack/knockdown

Is a W/mo good at tanking mesmers,eles.
Or is a W/e the better choice.

That is a broad question, and much based upon a small scrimmage vs. 8v8 team play. Good luck taking down a shutdown mes who carries distortion. It'll take a while if you can do it at all. As for tanking an ele, a W/Me is your best option, carry blackout and knockdowns.