Individual Pools
The champion pool should not be one set pool for everyone. Buying someone else's champs so they can't get them just because you already got lucky on yours and your items isn't outsmarting them, it's just further abusing the fact RNG was in your favor. It should be a different pool for everyone.
The downside to this fix would be that there's likely to be a lot of stalemates at the beginning when the easiest origin buff to get is Noble via Fiora/Garen/Vayne since they'e all 1g. Though since a stalemate means both sides take damage, it might be beneficial for game time.
It's just one of those odd hidden aspects that hinders fair play, resulting from a shortcut by the developers. Programming in one large pool for everyone is easier than setting up individual pools. But now that they're getting proper feedback and know from the overwhelming support the mode's getting that it's a good one, they can feel better about putting in the necessary manpower.
The argument against this is that it'd see people going for the strongest comp every time. But how's that a bad thing? If people are going for the same comp, then we get the data needed to know which comps need adjustments. As it stands, the luckiest person gets the strongest comp and has all the power to prevent anyone from competing, since they can both prevent them from building the same comp AND prevent them from finishing a different comp by buying and hoarding/reselling the champs they know the enemy needs.