EU has more players yeah but they are just thousands of horrible pubbies with no interest or clan presence in Strat, given the opportunity I guarantee there would be similar amount of clans actively participating in Strategus from both NA and EU, except maybe NA just doesn't have several stupidly large zerg clans like Grey and DRZ (yeah yeah LLJK, of course). Those clans would probably have even MORE imbalanced land due to this partition, bordermates of them will ally up and stomp the new entrants with ease since claims tend to be based around cities and there just isn't enough land.
Give that mirrored twice the size version of Strat a go, it looks awesome and its precisely what the majority of this playerbase has been clamoring for (probably). I don't want to see the vast amount of north america clans (there are a LOT and Strat will give reason for more and more to form) be bottlenecked in some stupid 30 percent section of the map, its hardly fair, and will simply not be big enough for all the drama the NA community brings. Either way if you divide the current map like this, I guarantee 80 percent of EU map will be UIF again within a few weeks, enjoy your fucked up Strategus balance