I have used WOB a great deal and I have found that the celestials work best as fill ins for other units .. rather than working together ... but I do disagree with the aversion to the Invictus variants. I have found them useful in the right circumstances. Using an Archangel, in a city, and running into another mech, going physical, and getting that possible crit, while spotting for others can be brutal.
Another thing is the prevalence of C3i .... and the fact that we have every clan mech, except the Uller and Vulture, on our list.
Hype it up, and let your opponent flood the table with ECM .... so many people will spam that ECM, expecting C3i, that if you don't use it, you leave them flat footed. For every variant that has the C3i, we have one that does not, along with the ability so seed the forces with clan mechs, as well, Especially combining mechs like the Marauder 9M, or 9M2, with support from something like a clan Puma .... no C3i, but a whole lot of hurt in that combo.
In addition, combined arms are your friends .... use the Tau Wraiths. Individually, they are not much, but the boosted communications gear they carry in their heads is a strong advantage when they are used as spotters. Coupled with their mimetic armor ability, you can plant them in good defensive locations, and call in large volumes of indirect fire. Tau Zombies are very tough, and you can spam them, as they are individual squads, so can be transported in any infantry transport. We get a bunch of tanks, as well, and many have C3i ... to include a variant of the LRM carrier ... having it indirect, for wraiths spotting, while it is connected to another level 1, is very doable, which means that when those mechs are in close, you can have it roll into direct fire, drop some pain with short range modes, and then roll back, and take targeting from the wraiths for indirect.
In the end, though, and especially with TW, you are going to pay a lot for a little .... learn to use things like LRM Flatbed trucks, and other filler units to build formations, and control the battlefield. Artillery, mines, and support fire with tag, etc ... those are your friends, just as much as the C3i.
Nahuris