Ive seen three Robins feeding at the same time in my feeding station. Some squabbling going on but I présumé Hunger with todays temps overcomes natural béhaviours ?
I've got two at ours and in the garden (possibly three) with some toleration and some squabbling too, very cold snap just now, maybe when it's over, they'll spread out again
I've only got the one, but he fair stands his ground against other birds who think they are going to share HIS feeder ...