Should I change my tank?

Hey guys!
I`m playing heroes of fantasy for WP 8.1 but it is actually nearly the same game only with a few more heroes.

At the moment I´m using Erondragas (S-Hero) and Hanzen (S-Hero) as tanks. At the backline I have Adept Rhee (S-Hero), Tao Yuan and Vera (S-Hero). For the panda I have candy can, which I still have to power up little bit. but thats not my problem.

Tanks what I`m not using are a second one Erondragas and Edvard (S-Hero). Should I replace Hanzen with a second Erondragas or Edvard? Or shoukd I stay everything how it is?

Thanks for your help!