Raiding for weeks in the same instance at the same boss would be stupid even for newer guilds. if a guild realy only has 1hr a week to raid, they just shouldnt be raiding. and these guilds would actually gain more overall to just kill Duke every week untill they can down 2 or 3 or 4 bosses in that 1hr then spending weeks working on the next boss getting no gear.
If you do not raid enough in one week to get down the instance that takes about 2hrs with average geared players and a few wipes added in once you know the strat and such, then you are never going to spend enough time to really progress on latter bosses. When under-geared and not a high quality raid group it takes a very long time to get some bosses do for the first time and even after that its not always simple ad quick.
1week resets are to be honest too long, all of the T1 raid content should be getting reset every
3 days for better progression, not being made longer resets or even options of longer
I'd still like a reason allowing more people to participate in this content has a negative effect on anyone.