They are not always brothers - lone males will often form a coalition with other, unrelated, males as this increases their hunting chances.
Lone males have very limited hunting success as it is the females who do most of the hunting but, if they can team up with other lone males, their hunting prospects will improve.

These coalitions are made up either of brothers or of any young or old males who have been kicked out of the pride due to the fact that they have reached breeding age (and therefore are a nuisance to the pride as, if they start mating with their sisters/mothers/aunts it will have a detrimental affect on the gene pool) or have been supplanted (in the case of older males) by a younger, stronger male.

I have seen coalitions, in the Sabi Sands, of young males( who had very new manes) and old males (who were clearly beyond their prime) who had very limited hunting success and depended mostly upon being able to catch quite small mammals unaware, in order to survive.

When more than one male lion takes over an existing pride, members of the coalition are usually brothers. The dominant male will mate the most, but his brothers (who share 50% of his genes) also take turns mating with the females, usually when he's too tired to do so or when more than one female is receptive at a time.

Further to Gerda's reply, I once witnessed a male lion mating with a female whilst the other 2 members of the male coalition were lying, apparently passively, nearby.

I don't know how accurate the information that I received is but I was told by the Game Ranger that, when a coalition takes over a pride, only the dominant (oldest/strongest) member of the coalition will mate whilst the others will keep a watch out for potential rivals and help to patrol and guard their new territory.

The male will, as a matter of course, kill any juvenile cubs that the female(s) have, when taking over a pride, in order that only his genes are present in any future generations whilst he is dominant.

Lion prides are formed of related females & their young and one male lion or a coalition of several males.

Young male lions will leave their pride when they reach maturity.
They will lead a nomadic live for a while and then form a coalition with other males and look for a pride to take over.

We have recently seen two males at the pan.

My question is about a pride and the number of males in a pride.

One only or more than one?

It is entirely possible that this is happening - or it could simply be that an established pride has moved into the area. The only people that could accurately judge this are the Game Rangers who work locally, as they will keep tracks of the lions movements.