Bonding Buns

Hi folks,

I have a mal (neutered) 3y rabbit named George , and he is the best. he has a little attitude as he is half dwarf, but otherwise he is very sweet. we recently went to a rabbit rescue and took him for a speed date with a 4y female (spayed) rabbit named Lucy. we wanted him to find a companion so he isn't lonely. we spent the day at the rescue trying their method of marathon bonding, and it went pretty well. George was immediately humping Lucy but no real fights broke out. however, it's been 2 weeks at home now and they've fought every time they have been in the same space. I tried cages side by side, swapping toys, blankets etc. tried neutral dates in the bathroom where neither bun is familiar, tried wiping everything down with vinegar and washing all bedding to create a neutral cage, and then last week they got into a massive fight. chasing, pulling huge tufts of fur, grunting, kicking each other, boxing etc. no blood drawn thank God! I'm just wondering if this isn't the right fit or if i should keep trying. it seems like both buns want to be the dominant bun, and that George really likes Lucy but Lucy bites him whenever he tries coming near her. I am just fostering Lucy until we know if it will work out, so i would appreciate advice as I've exhausted every other resource and feel like I've tried everything. should I give it more time? I wonder if i should try speed dating with other bunnies for George. Lucy was the only one they tried him with. thank you!