Well, as I built my own "succession wars board game" long ago (color pencils and 1$ big friggin' sheets of thin cardboard for the win!), I went through the whole order of battle (ah college, so little money, but so much free time) and if I remember correctly (I think I do, but I might have toyed with the values and remember those instead, but I'm pretty sure I didn't) the math fit, each army was roughly the amount of strength points as the number of battalions they were fluffed to have. But yeah, quality did seem to have an effet, but not a major one and not in every case.
Also, I dunno if planetary assault itself would be a good product, s'pecially for new players, as a boxed boardgame, but something derived from it could be awesome. The framework is good and keeps the battletech feel at that scale of strategy. Couldn't comment much otherwise as I can't think of similar scaled tabletop games I'd have played (nor video games actually...concentrating on just one planet in a interstellar universe isn't very common), but I'd be quite curious of other avenues.