Update: tested the prune version , and works perfectly.
But tested the changing the wallet.dat files. It works also perfectly, only at startup will rescan from the last seen block(can be 100....also). So look like the wallet.dat save the last checked block, and rescan from that one.
In my case, to save space, prune=10000, and changing the wallets in regular base.
Thanks again for all advise!