You could build your own templates instead of using the ones from RM. You could then name your own with a name that sorts to the beginning of the list. Finally, only use your own templates from the top of the list. This is my approach, and I only have 15 or 20 templates. They are all at the top of the list and they are the only ones I ever look at.
If you don't want to build your own templates, you could make copies of RM's built in templates that you want to use. Again, name the copies so that they go to the top of the list, and only use your copies from the top of the list. An additional benefit of this approach is that you can edit the copies but you can't edit the original templates. There are quite a few typo types of errors in RM's original templates - a comma out of place or a missing space, that sort of thing. If you use the original templates, you cannot correct any of those errors. If you use copies of the original templates, you can correct such errors.
I use an * as the first character of my source template names to put them at the top of the list. Most any other special character will do as well.