Even some divisions would get more viewers than others. The AL East (which would probably be the most requested) would probably get way more subs than the AL Central (which would probably be the least requested), with the NL East, NL Central, and NL West in the midddle. At the same time, the highest and lowest marketed teams lie within these respective divisions. Even if the moneys are allocated to each division and/or team equally, there is still a disparity when it comes to marketing and advertisement.
I am not saying that your idea is not a good suggestion (in fact, as a sub, I like your idea); I am simply saying that MLB would not allow it for the reasons I stated.
Like I said, the numbers can be dicey. Your not wrong in your assessment. I don't think the numbers would be that drastically skewed, but there would be a difference. Like you pointed out, even with Chicago being in one of the top three markets...the smaller markets in the ALC would drag down overall viewership...
But I am curious about how many folks would sub to a divisional EI package just to scope out the competition like I would. I mean its one thing to sub to EI to get your own team, but another if you're thinking competitively...
Whether the idea is good or not, or even competitively priced, I don't think its cut and dry as to whether or not MLB would gain or lose money off the endeavor. The question is whether or not a gamble is worth the risk if you are already enjoying a stable state.