death by swap

That was a description of trashing.
I would presume that executables do not make up much of the used memory. So reusing their pages will probably not be much gain.

Trashing is what happens when processes get their pages continuously swapped in and out as the system schedules them to run. Thats when everything grinds to a halt because each context switch or memory access needs to swap out some memory in order to make place for some other memory to be read in from the swap or the binary.
That can possibly happen when the total working set (actively used memory) of the busy processes exceeds the amount of ram, or more realistically, when the swap (nearly) runs out so there is nowhere to evict unused pages to free up ram - leaving space for only small chunks to run at a time.
Usually (in my desktop experience) soon after that the oom killer start kicking in, which causes the system to trash even more (as the oom have needs too) and it takes hours for it to be done.
When it happens I usually have no choice but to reboot loosing some data, so for me the oom killer has been useless and over-commitment the root of all evil.

Using up swap alone does not affect performance much, if you dont access whats on the swap. If you continuously do that - that's trashing.