I don't like mamoswine since it is so frail. Trust me man... Ttar is amazing and has saved me from sure destruction before. He has amazing bulk and the sandstorm he whips up adds more SpD to his stats. Tentacruel is fine. Starmie works for a more offensive option.
Edit Yah he's right you have a electric weakness then.
I have had great success with Tentacruel, but I can only keep him if I get rid of Mamo which is cool for stab priority ice shard. And the 50% Ttar boost is cool too. So many choices, i'd like to continue hearing everyones thoughts so we can continue editing/ drafting this concept of the most balanced team. (Well superbly balanced at least) Why are you not a fan of Mamo too much?
*Edit Could I use T-Tar's water weakness as bait to draw a water attack then switch to tentacruel?