I CERTAINLY do not call myself an expert on the game, but from my limited experiences I can say this:
I have tried 2 approaches to my Minbari fleet and both seem to work. The first way is a long range, heavy beam list. This excels with your Sharlin and Tinashi already. When you do the heavy beam approach, you'll want Tigara models and use the alternate version that has the 2 AD beam weapon. Now you just hold back and blast away! In this game, your opponent tends to miss out on shooting more often because of failed stealth rolls. When playing this sort of fleet, I end up loosing when the opponent gets in close as I am limited by my mini-beam weapons. If you are playing a standard 5 point raid, I would think that your Teshlin, and (eventual) 3 Tigaras will be enough for some good games.
The other style of play is harder, but also pretty darn good too! When you try to get in close, you attempt to cut your opponent with both 4" DD weapons as well as 8" DD weapons. This fleet takes the standard Tigara, Tortha and Troligan models. Because you are close up, your stealth isn't as great, but your AD goes through the roof! Although I have not done this yet, I would think that a Leshath scout would work well with this as will let you re-roll many of your misses. My particular build is a Troligan, 2 Tigaras and 2 Torthas.
Oh! And no matter what you take, you'll probably want 1-2 stands of Flyer fighters and about 4 Nials. Too bad the Sharlin is a War level because you'll need LOTS more ships to effectively field that one.