I'm of the strong opinion that we need to try have the issue of our internal balance fixed first and foremost. Having only 5 or so viable units out of our entire army is just no fun. Specifically I think we need to point out the clear mathematical disparity between the commander and the crisis suits, fire warriors and gun drones, and broadsides and hammerheads. In addition, point out that the kroot shaper, piranha and sniper drones offer our army very little/nothing that we cant get elsewhere for cheaper/better. People far more well versed in statistics than I, would you be able to draw come clear and unbiased comparisons to present?
As much as I want to offer suggestions to GW on how to balance the game, I highly doubt they will listen or implement any of these ideas. I think we might better achieve our objective by pointing out what needs to change rather than how to change it. In addition, comparing to other codices is quite valid in my opinion. Yes, in a vacuum you cant accurately draw an equivalence, but so many armies have very similar synergies to us. For example, the onager dunecrawler being buffed with re-roll 1's, vs a Hammerhead being buffed with 5 markerlights, is an example of similar units receiving similar points value in buffs. In this scenario the Onager averages 4.15 damage vs T7 3+sv targets, whereas the hammerhead averages about 2.3. From that comparison we can clearly see that the Dunecrawler does almost double the damage. It's a cheaper unit but this will be offset by the hammerheads slightly higher anti-infantry potential. Again, I'm no statistician so If someone more qualified can explain and present the same situation, I think this would help highlight that even with synergies taken into account, we're substantially overcosted for what we're able to do with similar units.
I don't know how useful sending this to GW will be, given that we're naturally weaker due to being an index army. It may be the equivalent of nagging the mechanic to change your tires while he/she's in the process of doing so. This was a bit of a ramble in a spare 15 mins I had at work so hopefully my point comes across ok!
Playing with a short reach since 2007