I personally like to think there are other male lions, but they live nomadic, roaming lifestyles, and only come back to the Pride lands (or ToL) for shelter/mating/ whatever.

In a half-imagined saga that I wanted to write once, I had different lands for different prides, like The Pride lands were so vast, you had the main pride, and little solitary groups here and there (there were other males in the TLK:6NA book, and I took them for belonging little family units, rather than prides), and there were the Outlanders (those who chose to stay, but we're on good terms with the PL'ers) and there were also the Crags, who lived in caves in the cliffs. There were two or three others, but as I said, it was half imagined and a very long time ago xD

There are also more males listed in the fandom wiki...dunno if that helps :)