Sharing roooms...

Uh so I have a question. I have three kids (g,b,g) aged 4,2 and three months. Youngest one will be 1 when #4 comes.

Should I put the two oldest together and have a co-ed room, and two nurseries or

Put the two youngest together

Or The two girls together

Or something else

I will add that my two oldest fight all the time as of right now and I know that I have plenty of time to think about this but I just want someone’s opinion early on so we can really think about it and help the kids transition easier.