Need a Second Sump Pump?

[Bojaby]

I have a 4 level split home. There is a sump pump in the basement. I had water coming down the walls from windows and window wall so had windows removed, dirt fill and graded away from house. Three wall of the basement remain dry and new dry wall is ready to paint. But the half inside wall continues to leak. Water pools under the garden level, runs over the wall between the brick and dry wall and has ruined the bottom 4 inches of dry wall. Would it be possible to install a second sump pump on the garden level? It would be under the stairs from the main level so out of sight on garden level. This seems like a better option than jack hammering the floor along the center wall and installing place for water to drain. I have now supposedly “finished” this basement 3 times but never solved the problem. I plan to sell and need to address this problem. Any help would be greatly appreciated.