I mean if you find that arrangment happens to you organically then great, but ultimately if you have three people all together, that’s three pairs. Four people is six pairs.
There’s no getting around that fact, that’s just how many combinations there are. And if just one of those pairs breaks up for whatever reason, then that mutual group stops working. It’s a very tenuous arrangement. It can also be a big strain on the other pairs when that happens, especially if it breaks with the understanding of what the group is supposed to be.
That’s why I think it’s best not to have that kind of arrangement as a goal. It can happen, but trying to make it happen creates a situation where some pairs will feel pressure to go along with it even if they’re not a good match, which is a recipe for further drama. If there’s no goal like that, then people can feel the freedom to keep their connection loose if they feel like it.
Always remember that “the market” is just a signal to the landlord that they could get more if the property were on the market today. It’s still their choice to squeeze you to take advantage of that. “It’s the market” is code for “because I can”.
Also they know that people don’t want to move every year or two, so they can absolutely raise the rent above market level without you wanting to leave yet. This has the effect of pushing the market higher. The switching cost is very high, so it’s in their favour that way too.
A landlord I knew about through a friend said they never raised the rent as long as their property is being paid off, because they would rather have it occupied and being paid than the tenants leave and the place sit empty.
Not to say that’s a good landlord by any means, but there is a choice. The market isn’t a mandate.