I have had cats who love other cats and cats who are not so keen. I have introduced anyway and have been successful. But I also have a larger place, so they can get away from one another when necessary. Only way to find out is to try. Be vigilant, so no one gets hurt. And patient. Even with the numbers I have and as 'used' they are to new comers, we have days of hissing and all. Just to let the newcomer realize that s/he is coming in as low cat on the totem pole, I assume. I ignore everything for at least 5 days. Short of outright physical violence (obviously).
My situation is totally different as I do have rather a herd. But I remember way, way back in the long, long ago.... we had Blue Boy. He was an only cat, and had always been so. I wanted one of my own (technically, Blue Boy was my Mum's cat) but was assured that Blue Boy (14 at the time) would NEVER accept another cat. I went ahead and got one anyway - and he loved her. Totally besotted, he was.
And so Muff came to me. Ultimately I hauled her off to University with me. But decided she was 'lonely' (I lived in a 1 room 'apartment' at the time. Not 1 bedroom - just 1 room) - a decision I arrived at based on the way she had taken up gutting her squeak toys (bored, bored, bored...). So I got Duty. A gorgeous little b&w kitten. Whom Muff hated. So much so that I actually took Duts back (she was a rescue kitten), crying all the way. But, thankfully, they advised me to try again so she and turned around and went back home. And she and Muff became inseparable. Hannibal came 1 month later (and so the 'snowball effect' began which has continued to this day....)
Try it. EXPECT all manner of hissing and spitting and annoyance and sulking. So long as it doesn't break out into immediate physical violence, you'll likely be o.k. (and so will they).