In other words you can't use them to OSRS gold obtain expertise. You will be given 300 Catalytic Runes and 1,000 Elemental Runes in case you select Runes. If you choose arrows you will be awarded 650 Spiritual Arrows.
Barbarian Assault. It simply does not make sense that you're being made to use your OWN Runes and Arrows in a game where you don't get expertise for using them. However simply giving you Spiritual Arrows that will allow you to never change does not make much sense. Captain Cain has asked Fiara make special Spiritual Arrows, which will reflect Bronze, Iron, Steel and Mithril Arrows. Each amount represents the level of this arrow.
You will be given 2,000 of each kind of Arrow each round. If you choose Runes you will be given 1,000 Catalytic Runes and 4,000 Elemental Runes per Round. Why Not? Barrows is a minigame that charges you riches with a opportunity to make wealth. With no dangers the game would be too simple and the costs of Barrows items would be on a rapid drop.
Clan Wars you're deciding to reflect your clan. Not necessarily a group. Additionally people might then just begin casting Bind on each other to attain experience and cheap RuneScape Mobile gold leave if they run out of runes which means they'd be abusing the game unless there was a reward or motivational factor for real combat.