Is that avatar a pic of ur umbee? If it is... nice! I went through 7 b4 I actually got myself a male...talk about bad luck. The last batch I got was 4 and I divided them in a 29 gallon show tank and by the end of the month with constant feeding and water changes I new I had 1 winner, a male. I gave the girls away, lol. Anyway, yeah, I finally put him with a similiar sized Dovii and he did not stand a chance. He wouldn't even fight back. I divided the 2 for about 2 weeks just so the umbee would be more familiar with new tank. When I took out the divider same thing happened. I tried everything from rearranging the insides but nada worked. I seperated the 2 until they were about 6" and it's now working out.. sorta except for the constant fighting. They're both a little over foot long and in a 100 gallon tank now and I had to divide again from the constant battering. Most of the time the male dovii was the aggressor but the umbee has more bulk. The only thing holding up the divider (egg crates) are few few suction cups and the substrate. It's gonna get knocked down soon from all the battering, I know it. I'm gonna have to make a decision and get rid of one of them soon and even with that, I feel the tank is way too small. I'm leaning towards keeping the umbee because I feel is a better looker.
You would be amazed at the gape of the p.bass I had 3 in a grow out tank all equal size and one (on different occasions) ate his bothers I came in as he had one in his mouth and seemed to be having some trouble since they were equal size and only found the others tail section. The dovii I agree will tear it up but if the p.bass gets even a slight thought it can fit another fish in its mouth it could be death on both parts
No one can say for sure what will happen, but Dovi's can be challenging to house with other fish. However you may not have any problems since they are very small. Give it a try.