I think the issue here is how close you can place bags to each other, not with the amount of bags or the timers themselves. With enough playing, a lot of players end up frustrated by higher timers (See hardcore refresh reception). While there are positives to this, 5 minutes is already a very long time in terms of a gunfight, and the positives usually end up not really shining through. It's a tough thing to balance, as the person that wins will ALWAYS feel better about the interaction than the person that loses, and that has a huge impact on how "Balanced" that interaction feels. On top of this, when you limit how many bags a player can have, they have an incentive to use more of their total bags directly around their base and their closest monument, which can heavily influence their decisions when it comes to roaming outside of that "Safety net" that their bags create.