4 Bunnies - one isolated - what to do??

Hi all - this is kinda complicated but hope u can help.

i had two buns - rosie and lance who bonded really easily. after a year selfish me wanted another bun and got cody (male) he fought with rosie but eventually bonded with her and lance was isolated - cody hated lance. After my heart breaking seeing lance isolated all the time and sitting on his own i got another male bunnie called oliver. I thought two pairs everyone would be happy. Oliver is now bonded with rosie and cody is will mix easily with rosie and oliver. Cody still hates lance and bullies him, chances and bites lumps of fur from him at every opportunity. Lance has become soo nervous, jumpy and sits on his own alot. He had GI statis twice recently and i think all the stress of the bullying is having an affect on his digestive system. I have had roise 4 years, lance 3.5 years, cody 3 years and oliver 1.5 years

They are all free range house buns (apart from rosie the last three are rescue bunnies).

What is the best thing to do for lance?? Cody basically sleeps alot and is happy just lying there but if rosie and oliver are lying beside him at night time he wont allow lance to snuggle in and lance has to sleep on his own. I know that lance just wants to have a companion whilst Cody is indifferent.

I feel really bad but have had thoughts of taking Cody back to the shelter as Lance is clearly not happy - i dont want to do this if i can help it, especially after all this time.

I did pen cody in for a few days and the trio of other bunnies works well.

Any advice anyone as i am sooo stressed worring about the poor boy.

Would you be able to get Lance a female partner and keep those 2 separate from the other 3 just a thought

If they have free roam over the house maybe split the area up into 2 halves and split them into 2 pairs. Say with the original pairing of Rosie & Lance and put Oliver & Cody together? If you do it with mesh in the doorways then the buns can still sit with each other but Cody can't bully Lance. Not ideal but better?

Or if your main concern is overnight then only pair them up overnight and let them all run around together during the day, but if you try that make sure that Cody doesn't get jealous as this would make the bullying worse.

Tricky situation, good luck!!!

Thanks for the advice guys. Unfortunately i couldnt get another bunny - though i have thought of that (husband says no more!), and i couldnt separate ollie from rosie as he follows after her like a shadow. Rosie, Ollie and Lance get on well as a trio, even though lance has a wee chase at ollie the odd time. In the evenings i let them into the spare bedroom so lance can get a break as cody is quite agraphobic and wont follow him in there so at least lance has some respite.

I dont know what the answer is - is it cruel on lance to let things continue this way?? Is every rabbit meant to be bonded with another?? Funny lance is the biggest out of all four of my bunnies but the most senistive.