I dont think you have understood why omen is in pro so often... He's versatile... Need an entry to dodge sentinel util... Shadow step, need smokes, yes, need one ways (sure now they're less) yes, need a literal unavoidable blund thats guarenteed to hit if they're there and it passes through walls, yes... Omen is played in 80% of games because his util is that versatile... And harbors wall, like if you can position correctly... Gives you that same versatility more than omen's smoke.. Its just that he doesnt have any other r real aggressive tools to support a fight like omen... Which is why riot made storm surge to try and give one... But i feel like instead you make a cascade that does the near sight slow... It gives more value and performs similar to paranoia... And then with the 2 coves as your long range smoking tool, that while you can have only 1 up at a time, you can decide when you want to block bullets or not compromising on vision Denial.
I may be innaccurate on proper balancing but the fundamental mechanic that should make omen and harbor different is in the movement expression omen can perform while harbor performs an expression of a contact duelist sort of mixed with an initiator.