guest_1458306682869 :
Part of being in a guild is sharing tactics and helping others grow. Why not allow the option to sell players to fellow guild members so we can help them grow?
There are player strength limits for each division so that's an immediate barrier to selling or donating players to a lower league guildmate. If those limits were somehow relaxed for intra-guild exchanges it would mean that progress depended more on who you know rather than how well you play. The game would be unbalanced.