Had my thinking cap on mate and have come up with an alternative list:
How about:
Calgar - 275
Tig - 165
10 Marines - 140
5 Marines - 70
5 Dev Centurions - 3 Grav Guns, 2 Lascannons, 5 Missiles, Omni Scope - 470
3 Dev Centurions - 3 Lascannons, 3 Missiles, Omni Scope - 290
Storm Raven - 200
Tau Commander - Iri Armour (2+ Save +1 T (T5)), Vect Thrust (hit and run), Stim Inject (FnP), C&C Node (Ignore Cover), Multi Spec Suit (TL weapons), Onagar Gauntlet (1 str10 combat attack) - 170
10 Kroot - 70 (Can infiltrate to block the White Scar Grav Gun Bikers scouting too close towards the Centriouns or Outflank)
Very similar to your list, basically the Tau Commander sits in whichever Centurion squad (I suggest the 5 Centurions as he has Hit and Run, plus the same abilities as Tig, so Tig sits in the other squad).
I almost think you could drop Tig from my list, give the Commander a 4+ Inv Save for 25pts, gives you lots of pts to re-invest into the army... (Another Centurion)
How about:
Calgar - 275
Tig - 165
10 Marines - 140
5 Marines - 70
5 Dev Centurions - 3 Grav Guns, 2 Lascannons, 5 Missiles, Omni Scope - 470
3 Dev Centurions - 3 Lascannons, 3 Missiles, Omni Scope - 290
Storm Raven - 200
Tau Commander - Iri Armour (2+ Save +1 T (T5)), Vect Thrust (hit and run), Stim Inject (FnP), C&C Node (Ignore Cover), Multi Spec Suit (TL weapons), Onagar Gauntlet (1 str10 combat attack) - 170
10 Kroot - 70 (Can infiltrate to block the White Scar Grav Gun Bikers scouting too close towards the Centriouns or Outflank)
Very similar to your list, basically the Tau Commander sits in whichever Centurion squad (I suggest the 5 Centurions as he has Hit and Run, plus the same abilities as Tig, so Tig sits in the other squad).
I almost think you could drop Tig from my list, give the Commander a 4+ Inv Save for 25pts, gives you lots of pts to re-invest into the army... (Another Centurion)