The Guardian tends to waste too many actions on protecting waifs which die and are re-summoned every turn. If you're going to use it, make sure it's to support another model, as said above, as opposed to a waif, but honestly, 7 SS is quite a high purchase for a master that benefits so much from A&D and Alyce(21 SS right there).
The Warden seems a strong choice for several reasons, though I have yet to purchase one(or two).
I actually recently acquired a Molly boxed set and intend to try out Crooligans, based on a Negative Flip podcast/radio episode awhile back challenging people to use them effectively. I look forwawrd to it, even if there are models that I would rather use for efficiency.
As stated above, the Rogue Necromancy is slightly squishy. Once it poses a threat, you can often expect it to go down in one turn, or sometimes just an activation or two.
Joss and Lazarus I unfortunately have no experience with, though Joss seems slightly overpriced for what he brings with the models currently available.
LSPA's work well, offering decent damage output and a couple scrap counters afterwards. If you're looking for scrap counters(which is not the best way to get SPA's), look at the Hunter: 6 SS on a 50mm base = 2 SS per scrap counter.
I've used Teddy several times, fairly well. For a large beatstick, his flight helps him get aroun the board since you don't have daydreams to pop him out and around. I find that people tend to primary him(and yes he can go down rather quickly) to their detriment, as Levi is such a threat himself. One list I used Killjoy and Teddy, and the opponent was sweating bullets. It's not a competitive use of the models, but it's fun and really drew fire away from Levi and the waifs.
Honestly, don't discount many models with Leveticus at all.....I've run quite a few with him, and have enjoyed it every time. I followed the same path as Lucidicide(I am not proclaiming myself a master or his equal) having been initially irritated with Alyce, then happy as I learned her place. After reading his thread I was pleased to find that I wasn't alone in the learning procedure.