I thought that you could just enqueue jquery and all the versions
would be loaded
All version of jQuery? No. That would be foolish. You’d load a tremendous number of resources and have a high probability of conflicts.
If you are referring to the built in dependency handling, then you can enqueue only the dependent script and have the other dependencies load automatically, assuming the scripts are all registered correctly.
I am trying to figure out how to get it working so that plugins won’t
make it crash.
Some plugins will make the site crash (or break if not actually crash) no matter what you do. Some plugins (many) are poorly written and many have not been updated in a long time. You can’t fix those problems by hacking your theme. You can’t compensate for the infinite combinations of bad code, old, code and weird code. Write your theme properly and hope for the best. At least you have the moral high ground someone complains.
If you must use an old, bad, weird plugin you will have to hack it into compliance, or write your own to do the same thing, which I’d recommend over reverse engineering and remodeling someone else’s strange idea of good code. If it were a decent, up-to-date plugin you wouldn’t be asking what is wrong with it or you’d be asking about some obscure edge case.