To edit the TT units, you're looking for the protox.xmb, not the proto.xmb. The proto.xmb is from the first game, whereas the protox.xmb includes both the original and new units.
Lots of information of proto(x) editing in the modding forum... although getting a response from anyone is difficult over there. Here too, but not quite as much.
Your Divine Overlord
KING JARED
Aw, hell, I dunno, she had some tig-ole-bitties, d'int she?
big.vitt@gmail.com