I have a similar set-up for my cabin. I have 4 GC-2's, 6 solar panels, a 400 watt 12 volt wind charger, a 3500 watt generator and a 1500 watt invertor
In the cabin I have a mix of 12 volt (lights, RV furnace, water pump) and 120 volt ( TV , coffee maker, fan, etc).
The solar panels are run to a 100 amp controller, wind charger has a built in regulator. I have a 4 stage, 80 amp RV charger that I ran a single cord outside that I can plug into the generator. If there has been no sun or wind for 3-4 days I run the generator for about 4-5 hours to charge the battery's.
Do not need a transfer switch I can take 5 minutes to start the generator and plug in the cord for the charger.
As far as having 3 different charges coming to the battery's it does not matter. The battery's will accept the highest voltage coming in. I do have the solar controller adjusted(14.2v) close to the wind charger (14.1v).
It has been working REALLY well for going on 6 years.
All told I have about 2100 hundred invested. Power company wanted 6700.00 to run power to me plus the cost of whatever I use.
I once figured it out over a 20 year time frame, with replacing battery's every 6 years, generator once. It cost me around 20 dollars a month. Compared to a minimum of 65 per month from the power company.