They have the same leadership as regular saurus. Without a Slann being in them makes the unit a bit tricky to take, while with a Slann they're practically a given. Against most units in the game these days that enemies throw at Temple Guard, I think it's safe to say that majority of the time they're going to be using their HW&Shields. Personally I think Halberds are crap compared to the extra armor save for just one more strength. Because in combat, to the front of course, TG go from having a 2+ save to a 4+ save in combat, not including strength modifiers. Personally I wish TG were like the models and could wield halberds and shields together, but they don't.
Personally I think I'm going to see how they do in a less than 2000 point game, I'll probably take no more then 15 cause I've got a 1500 point fight coming up. I'll let y'all know how they do.
Oh, and as for the RG's magic weapon 25 point limit, if I do give him one, it's always the Sword of Might, so it's the best of both worlds, HW&shield and +1 Strength.