I find my kribs and rams get on great with each other but my kribs chase my opaline gourami's and otto's quite bad so i agree with james, lose the krib and up the rams.Personal experience get sexable rams and 3 of, like the gourami's there better in a ratio of 2f:1m as the males can get quite aggressive when they want to mate.
Best of luck, the tank looks lovely.