I don't think they're 100% wrong here. It just started but the player ratio is already 2:5. As more people join in, that gap is likely to grow as people joining for the reward choose the side that's going to give a better reward. It doesn't feel like competition when the choice is "more reward" or "less reward".
In this case the module reward is so completely useless that I'm going to be quite happy to support Kaine and therefore only get five useless modules cluttering up storage until I remember to get rid of them rather than ten.
(Of course if everyone did that it wouldn't work, but it looks like a fairly safe bet at this stage)
Whoever is winning in the first hours will just win no matter how long the CG takes as the trend gets set in stone.
True. Though that would happen even if there was absolutely no difference in rewards for either side win or lose - there have been plenty of CGs of that nature which have
still started with and maintained a 4:1 ratio. There's generally no reason to expect that the first hundred people to pick a side in a CG will be doing so for reasons massively unrepresentative of the wider player base.
balancing out the larger population advantage that Mahon has with pledged supporters.
Mahon probably doesn't have (measurably) more supporters than Kaine - they have a larger Powerplay territory, but that's inherited from Powerplay 1. Inara suggests that Kaine has marginally more supporters; Kaine has gained slightly more new systems since the start of Powerplay 2 than Mahon has (though conversely Mahon has reinforced more of their existing ones); the rare Kaine vs Mahon competitive Acquisitions have gone both ways rather than being walkovers.
The ratio in the CG is at the very least significantly wider than the difference in supporter counts.