I live in Latin America, there are no professional animal rescue shelters just private homes with usually poor people trying to help abandoned animals.Personally, my feeling is that a situation such as you describe might not be an improvement from the side of "is their their well being being improved ?". Rescue shelters have full time staff, vets, trained personnel and financial resources unavailable to most people. So the question is ...does your personal situation allow you to be in a position to improve things for them ? How often you have to be away from home, how many folks you can depend on to help you all factor in here. And is your property subject to limits on how many dogs you can keep.
Dunno where you live but weather is an issue here. If your hitting high 80s or low 30s, that can be a significant issue. Aside of the physical well being issues there's the other side .... how much human interaction can you give them ? At some point this might become an issue with neighbors. We have a large 3.5 acre property that was owned by a breeder, also has 3 outdoor kennels and a grooming room. We have 2 dogs, 2 cats and sometimes we have guest dogs and my son's 2 dogs. Historically they have had the full run of the fenced in property but storms and fallen trees have created gaps in the fence and will likely be July before we catch up.
Normally the dogs are outside in spring / summer / fall on days that we dont have heat or AC on.... they come and go in and out as they please. They want in they bark. I work from home so Im with them pretty much 24/7. And it' me, wifie and 2 adult children. One is a pilot so he's here mostly, the other is a student. The house is a 200 year old dairy barn with 5 levels, each separated by a hinged baby gate. Every new arrival has had issues with the other animals when they arrived, gates provided for socialization opportunities but inter-pet aggressiveness is not tolerated ... at this point everybody eats out of each others food bowls.
Is the plan such that they'd be platooned ... in other words ... 2 inside on M-W-F and 2 inside on T-T-S ? One thing we've become very aware with of late with our latest addition requiring some medical care on our part is that the other dogs are affected by what they perceive as "special attention". The dogs were fighting, marking and humping each other all of a sudden for reasons we didn't understand.... so the indoor / outdoor situation may cause some rivalries.
Aside for that, if you have the resources in time, environment and other items noted above a secure fence and adequate environmentally controlled shelter would be the 1st step. Adequate financial resources will be required to provide proper care and diet. No "Purina Dog Chow" (not a knock on the brand, Purina does have quality product lines) but the stuff that one can buy for $20 for 50 pounds is not a healthy diet.
Your goal is admirable and anyone without full knowledge of your resources and time that you can commit won't be in a position to judge. But going in you have to understand the challenge this will bring ...good pets require physical and mental stimulation beyond that which they get from one another. A fair number of pets that are brought into shelters are ones that were taken away from owners because over time because of owner's deteriorating health or finances, they could not provide adequate care.
Many more thoughts come to mind but it starts with "can you give them better care and more attention than they could get at a shelter. One thought I'd suggest is partnering with a local shelter and fostering dogs ... this way you have a fallback situation whereby if you are called away got family emergency or whatever, you have a support structure behind you.
That's why I kept the puppy dumped at my gate and took the dog that was being attacked at the private rescue shelter - they had to keep him separate in a room for his own safety. He's a lovely dog but they currently have 30+ dogs and can only really handle 20 so his life was bleak and no one wants the puppy.
I have a large fenced back yard and a large undercover verandah. There are no limits on pet numbers. Our climate is tropical but I have heat mats and wind-break shelter for winter.
I walk them in a separate fenced paddock where they can run free daily (unless it's raining) for a change in scenery. I work from home. They're learning to enjoy a car ride when I run errands. I cannot mix them with my indoor cats (also rescues) and my indoor neurotic dog (she was beaten and I got her from the street) - that is a recipe for disaster and unfair on them. It took me 2+ years of gradual and controlled introductions to get a harmonious balance with the 5 of them.
Aside from having the puppy - which I never wanted - I am only interested in taking special needs dogs. Toby limps due to a motorbike breaking his front leg and someone kicking his back leg. Trixie has three legs due to a car hitting her, one front leg was amputated and the other was broken but healed.
The idea is for them to enjoy each other as a little pack. They've only ever lived outdoors but they do enjoy it when I read or take my laptop out onto the verandah to be with them after dinner.
I've attached a couple of pictures of the local rescue shelters. One is the home of an old lady who has 30+ cats/kitten and some dogs. The other is an old man who has a dozen animals and the last is a young girl with the 30+ dogs where Toby is from. They're all good people but there is no money except from donations and no government assistance or training.
So yes, I absolutely can improve their quality of life and I've improved their diet 1000% already with my home made recipe, fresh bones, etc. I've had dogs all my life but this is the first time I'm going to try having an indoor gang and an outdoor pack... so I'll probably come to DF for sanity breaks😜 as well as advice.