Coming from a small guild myself, to an extent I can sympathize. I joined it late in Wrath, on an alt, because I could do some ICC on it there. Their core Group all but went MIA shortly after Cata dropped, and The current "core" is a few of the core group coupled with the saturday 2nd/alt group.

Anyhow, the departure of some of the core raiders probably set progression back some, though we had 10 ppl show up for the first month or two. We also started on Halfus. At this point I'd swapped to my main, a healer. Don't give up on Halfus. It very well could be that it wasn't the tanks or healers fault per se. Some combinations of drakes are harder than others (at least at first). The BIG thing is knowing what each drake does (buffs him/debuffs him). If, as an example, you have Nether Scion, Slate, and Whelps, you have to contend with a Mortal Strike and increased weapon speeds if the first two are left down..When we left Nether Scion down and let Slate and whelps out..our tanks got flat MURDERED. The rate at which the MS stacked was too much. So we swapped strats, left Slate down (we be lazy mon) let the other two down, and Halfus attacked slower, had a chance to miss, and did less damage (i