I had a 101 twink DK, about 810 ilvl. They are really fun, but I kinda run out of things to do. Great for farming the regular zones (other than Suramar). I thought about doing a 5 x twink team for giggles, but tbh even 2-3 like you have here is pretty much overkill for anything in the game that isn't fixed to lvl 110.

Actually one great use would be having a 101 DH twink to speed-run your 110 teams through Nelth for AP / order hall resources chest farming.