Salting meat is a complex science..
From what I have read, and from personal experience, when salting foods about 2% is the maximum for a non-salty flavor.. And salting ahead of time, say 24 hours+ or so, the salt penetrates so you don't get that blast of salt on the tongue.... Salt, like others have noted, originally pulls out moisture... Then, through equilibrium, the moisture re-enters the meat to eventually reach equilibrium throughout... and the meat goes through a tenderizing process breaking down proteins... all of this is temperature dependent.. see specific recipes for those parameters... 38F for initial application to reduce bacterial growth, then up to ~50F for continuing the process....
On another note, salting meats for a dried meat product like proscuitto, to prevent bacterial growth, 2.75% is the minimum and with the addition of cure, adding another 0.25% cure/salt, you reach 3% salt in the product... THEN, with the moisture reduction from the aging process, about an Aw (water activity) of 0.85, bacteria won't grow..
Higher concentrations of salt initially, kill surface bacteria.... then after some penetration, time and temperature dependent, a light rinsing is usually employed to reduce the salt content and final meat conditioning is continued...
It is important to note... mixing and matching of methods can cause problems... each method must be adhered to and not cross matched to other processes..
Examples of the process and time/temperatures employed for country hams...
...Finished product ~4% salt...
https://www.meatsandsausages.com/hams-other-meats/country
..About 6.35% salt added inititally..
https://www.meatsandsausages.com/hams-other-meats/ham-country-american