With the fluctuating flow of players in enlisted different factions had periods of time where they have less players than others, which have resulted in the matchmaker seeking battle with a br range, that in some cases results on low BR player fighting in higher BR battles.
This can be frustrating some times if the battle feels one-sided and also can be considered a waste of time by some as lossing specially like that results in very little XP been earned.
So adding a XP multiplayer to players that end up fighting against a team with higher BR players would help to keep them in the battle as well as it would help under populated factions to regenerate a higher number of players on higher BRs which would help reduce frustrating battles where one side has a larger amount of higher tier players than the other.