Grafted trees are the normal method to get small trees for limited space, these can be bought already grafted to dwarf root stock or you can buy dwarf root stock and graft your own.
Pruning alone will limit top growth to a point but it will also create weak branches at some point, which translates into damaged trees from wind broken limbs.
Trees grown in containers need to be considered Bonsai, you will be lifting and pruning both top and bottom at least bi-yearly to keep the tree in the same container, moving to larger containers will slow growth but it also means heavier and heavier containers (which aren't inexpensive).
The above goes for root control bags too.
Crowding trees is asking for disaster from disease and or insect pests, the closer trees are the easier it is for a disease or pest infestation to spread to the whole orchard.
these are the cons, if you are looking to reduce your time spent tending the trees, grafted dwarf or semi-dwarf trees are probably the best choice since they can be in ground and will need little attention once established (compared to container trees or in ground pruning).
More trees are killed every year by root control bags used as if they were containers for an orchard, people forget they have to
water these trees just as if they were in a container above ground or in a nursery (the setting they were developed for).
Crowding (intense planting) can see all trees decimated by any of the blights or other diseases faster than you can get it under control, it can also lead to reduced fruit production of all trees.
On the plus side, it can make it easier for pollinators and that can mean a great fruit set, but then you have to go in and thin the fruit to protect the branches and if the crowding is thick enough, that can be very hard to maneuver in the orchard.
In such a situation, where I had limited space and wanted the most variety of fruits, I would look at devising a planting scheme that made full advantage of dwarf trees (these can usually be within 10 feet of each other with just a little pruning necessary to prevent tree overlaps).
Redhawk