If they enjoy each other's company it could be great.
They do take time to settle as adults, and to leave the bad stuff behind them. I have a foster here who has been here for several months and is also only just starting to settle hormone-wise (about four months since desexing). Damn testosterone, lurking about where it's not wanted!!
Plus if he's been through a few different places - first home, pound, rescue etc - he will take a little while to figure out that he's now home to stay.