I'm not 40K-gamer, obviously, but I thought I would take a stab at this. First f all, AM does far better than this. They don't have to approximate exactly the STR and volume of shots. They can spam a volume of shots with higher strength and larger blasts. I've fought AM (although I prefer to just call them Guard still) that could put down 20+ strength 8-10 Large blasts per Turn. Granted, this was a list tuned to the absolute hardest, but it follows the same logic as the Tau one. Variations on it had it spamming even more smaller blasts and many of them also ignored cover or had other crazy benefits. When it comes to firing for effect, the AM is just as nasty as the Tau (they just get there with a different look).
Then there are a huge number of variations based on spamming Dreads, Gravity Guns, and small arms. If you include Mortis Pattern Dreads and various other gun batteries and/or artillery you can supercharge any Space Marine army (as well as AM). Of course we cannot leave off the high strength spam special guest stars of this Edition, i.e. the bugs. The volume of fire provided by FMC shooting batteries which can in turn be backed up by squads of three MC gun batteries bearing down on opponents at high speed also bear special mention. Poison spam from Dark Eldar may not have quite the range and power but it kills just as effectively. Those hideous little mini-boats put down obscene amounts of power and you can spam them like there is no tomorrow. It only takes a few of them to survive (or go first) and you can blast most of the spamming shots from Tau off the table. Crisis Suits are, after all, not armor nor are any Riptides. Nothing says "up yours" to what look like giant robots than spammed poison shots.
While I agree that the specificity of Tau high STR volume seems hard to match shot per shot, you don't have to do that. You only have to match it for results and that isn't that hard to do. I don't begrudge the Tau players their cheese anymore because we now all live on the Moon and it appears the legends of it being made of green cheese are true.