Changing the current structure to short rests would greatly empower full casters, even if you divide the number of spells slots recovered. Moving short rest abilities to long rest by multiplying their use would fit much better.
I can see an argument for it, especially if you have a short rest caster that knows they're going to be able to get their spells back after 1-2 encounters. Having a deep spell capacity is useful in 5e, but not as useful as earlier editions because so many of the strong spells are effectively 1/encounter due to concentration.Why do you think full casters would be empowered if their total slots were divided by 1/3rd or they were switched to Warlock casting?
Warlocks casting might work, but dividing the spell slots won't. How will you divide spell slots with less than 3? Can casters choose which ones to recover (in which they'd take the higher level ones). I tried something similar with dividing by 2, and found a huge issue once you got to 6th level spells. Dividing by 3 is going to be even more difficult.Why do you think full casters would be empowered if their total slots were divided by 1/3rd or they were switched to Warlock casting?
Refreshing spells on short rest would be best with spell point variant.
Just make 1/3 or 1/4 spell points recharge on short rest.
Context. With a 6-8 encounter day you need the SR.
If you ask for me to generally chose one of them and leave out the other it is LR of course, because it is kind of more "realistic"

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.