The whole thing with male companions is they are always paired with a female companion or the female companion is the "prime" companion.
For example:
Ian-Barbara,Susan, Vicki
Ben- Polly
Jamie-Ben and Polly, Victoria, Zoe
Harry- Sarah Jane
Jack- Rose, Martha
Mickey- Rose
and so on.
So far the only males not having a female companion in tow was Wilf (and technically he was connected to Donna) and Craig. Both those companions were specific to special episodes outside of the regular series. I'm not saying a male companion by himself isn't possible but it seems like the pattern of the series says otherwise.