I would start with pairs – try Amy and Alfie together in one session, then try Daisy and Alfie together in another session. I would work to get Alfie’s bonds with each of them to a pretty stable place (at least in the bathtub, not necessarily to the level of living together) and then introduce all three and hopefully it won’t be too chaotic. It’s up to you whether to try the trickier pairing first or the easier pair. In one way, doing the hardest pair first means it’s probably downhill from there. Then again, I’ve heard doing the easiest pair first can give you a buffer between the hard pair once you work on them. Personally, I think it’s just a matter of what you prefer.

I know this sounds drastic but I”d try all three at once. Put the pair into the tub and then introduce the third – see what happens. Sometimes a bond can shift about without the other being there. Both types have merit of course and dealing with two is easier than three. But IMO it’s good to see what happens if they’re all in the boat at the same time to start with – you can also gauge who’ll be the easier of the two with the rabbit.

I’d also suggest swapping out their litter boxes with one another a couple of days before hand. Your freshly neutered male’s scent will be changing for a couple of weeks after the surgery.