i like ur mega swampert team the most :] the only change i'll personally make is change Zyg to Ferrothorn to better deal with Tapu Fini / Tapu Bulu / Tapu Lele. The former two gives Swampert trouble while you don't really have safe switch-ins to Lele outside of Gothitelle, which can't do much back (although giving some special bulk to ur lax would help)