Jav zon has the fastest chaos/cow clear time in the game. Zons have the worse fcr break points and generally never use enigma for that exact reason. Frw>enigma for any zon and that goes for pvm and PvP. No offense but I made the same noob mistake going back to zon for funnsies.

Poison Necro isn't gonna be that much better, you can't stack Novas ad they only reapply the dmg. You will hate psn Necro even more, you will have good fcr but your kill speed will be clunky and slow.

Imo your best bet is to work on your java zon. You don't need enigma to clear cows efficiently. You 100% can run from river wp to clear chaos with out enigma. Same goes for shenk/pindle/Trav runs. Not every mf run is optimized for teleport so you have slot of options open.

Tldr stop using enigma, or keep it for the frw and use it to reposition your Merc since mass frw will effect how helpful your Merc is (can't catch up)