If a player solo captures a flag he gets 100 xp.
If a group of 2-5 Demigods captures a flag everyone gets 100 xp.
Imagine a scenario where Player A captures a flag alone and then loses it to a crowd of three players and then captures it again etc. Now Player A gets for example 800 xp from flag captures and so does the other team, Player A's team allies however get 0 Xp from flag captures. That means staying together is artifically rewarded while spreading out is punished. The XP must be split, capturing a Flag needs to be as good as single guy as as Team or it totally messes up the game dynamics - Nobody will solo cap a flag in early game anymore as this is lost xp. I think this is one of the main reasons why keeping together as group of 3 Demigods is so efficient in 3vs3 - always wondered why they aren't behind in levels vs spread out teams.
If that is for some reason intended (what I doubt to be honest) why is the XP for Reinforcements split?