MI-28 will give you a lot of fire power but it'll be a maintenance nightmare over long run. Plus remember, Z-10 brings in a lot of new features and you can get it with tot or semi-tot. Either way, it'll set the basis for the local industry, like it happened for the JFT. I think that alone, is priceless and saves hundreds of million $$$$ in the long run.
And no, I am not crazy, you kind of already are in the mix for too many heli's. You have Cobras, which won't go away, in fact the numbers might increase and upgrades will come. Then, you are looking into MI-28 and MI-35, so that's two types. Then Z series is also a reality now, specially with 3 test choppers being given for free. In the long run, I'd imagine Cobras will be retired and then the MI-28 will retire. So you might end up keeping Z's, MI-35 and some advanced Super Cobras. That's three types of choppers. Not that uncommon. Choppers aren't really that multi-role so you kind of have to have a few types.