Adjacent doors hitting each other

Another solution: Make one of them close to avoid clashing.

I reversed my kitchen door so it opens into the hallway instead of into the room. That means it can clash with the cloakroom door if that's left half open. I solved it by fitting a (very gentle, in fact modified with a weaker spring) automatic closer to the cloakroom door, so it doesn't stop half open.

Rehanging a door can be tricky but is perfectly doable with reasonable DIY skills. It's one of the simplest tasks for which you need a decent set of chisels (in fact it's the main reason I even have chisels). The job needs proper planning: when I did mine there was enough space on the new side of the frame to make it simple but had it been on a different (non-structural) wall it would have been much harder.

I did indeed end up putting two stops on one of the doors at the top and bottom and it works ok.

One key thing is that I put the stops on the door that faces the length of the hallway. This is important because you don't want to have a door stop jutting out into a corridor or hallway where someone could trip over it or knock things into it, like bags or luggage.

By putting stops only on the door at the end of the hallway they worked fine and created no problems.

I had this same problem with my front door and the adjacent garage door. The solution was a unique doorstop that is slightly longer than normal and has a roller on the end of the stop as shown below:
6 inch doorstop with roller
enter image description here

If one door is narrower than the other it should be installed on the narrower door.
Here is the link:https://www.doorware.com/site/product.cfm?id=349175