A little gamey, but all their formations are expensive and have low break points. Start with the most expensive formation, kill enough to get the points and move on.
Tau probably work well against TL armies because they can concentrate their limited, but very effective, firepower against a small number of high value targets. My only advice for a pure Titan army would be to make sure you maximise your range....any weapon with less than 100cm is probably right out against the Tau. If you are playing AMTL, I'd go for a Mechanised company or two, Hydras+T-Bolts, possibly Marauders and lots of Crusaders
Hammerheads look awesome....until you realise they are 75 points each. The only one that hits on a 3+ is the Mk III variant with a 35cm range. Are you working off the latest list on the Wiki?