Block count is simply the best base variable to compare everything else (mass, cost, etc) with. All the other variables twist eachother in some way, but block count is just block count.
Advanced is better than hull, yes, but it's also heavier, and the ship that only uses hull is probably not trying to tank with light armor, and has replaced the advanced armor with shields, and will also go faster. It's not unfair to use block count as a metric here.
Well, sure, if you're replacing my example by another one, you can say yours is balanced indeed. But ok, I admit that you can't just swap armor types, keep the same systems and call it a day, that wasn't a very realistic example.
The bigger one may have the same mass, but it will NOT have the same price. You know why? Because shields cost twice as many capsules and advanced armor weighs 2.5x as much. 3 mass of advanced armor might cost 300 capsules, but 3 mass of shields (regen or capacity) costs 1500 capsules. Price is probably the best metric for measuring your bang for your buck, but armor is cheaper than shields.
I didn't mention shields. I could make a long-range ship with no shields, no heavy armor, but high thrust and light spaced ablative armor to counter smart missiles for instance. Granted, this would certainly be extremely dangerous to fly, but it is feasible. Actually since shield tanks are heavier than armor tanks (according to you), we could also consider the opposite case where the small ship is a shield tank and the bigger one an armor tank, should that be unfair because the armor tank has more blocks than the shield tank?
Besides, in your example, you argue that it wouldn't be fair because the big one is very likely to be an expensive shield tank... so you're actually using price as a metric here and not block count.
Mass does not mean the """"effectiveness"""" of each block in combat, and if it does, it certainly doesn't mean what you think it does, because then advanced would be better. Compare 1375 EHP per .25 mass (assuming ion AND assuming no drop in shield effectiveness, which shields have but it makes calculating little things a pain in the ass) with the 4000 EHP per .25 mass of advanced armor.
And no, heavy blocks are NOT more expensive. Standard and Advanced are both less expensive per mass than shields, Standard especially with its whopping low cost of 100 capsules for 3 mass.
Blocks designed to be used and/or give an edge in battle
are heavier: advanced armor blocks are heavier than standard armor because they grant better protection, decorative blocks don't weight much because they don't make the ship much more threatening. I never said that each block's mass was perfectly balanced (it's a beta), but there's an intent to link mass and effectiveness.
Also, to address your example... well... I don't really see what you're trying to prove here. Not only those blocks can't be compared with just numbers (both shields and armor have their advantages and none is better in all cases), but as I said Starmade is far from being balanced atm.
(you also made a mistake: it's 687.5EHP/0.25mass per shield capacitor with full ion (110*2.5/(1-0.6)), assuming there's no diminishing return)
[Edit: I missed that part but if you're comparing the price of two blocks to say heavier blocks aren't more expensive... don't compare the price per mass.
I also said "heavier blocks tend to be more expensive" not that they're always more expensive, granted I thought the difference was more pronounced than that though]
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You seem to think I'm trying to argue that shield tanks are better than armor tanks or vice-versa. I'm not, I'm only saying that either price or mass is a better metric to compare ships. I could understand that mass is a flawed metric because you can have a super light ship which is actually hard to build, but block count is at least equally flawed since you can also make an expensive ship with very few blocks as well.
Comradecolonel I agree, not to mention it looks good
That's not what I said. I was saying that shields cost more for the same weight and have less HP than advanced armor, not that they weigh more. Armor tanks typically weigh more because shield tanks have less overall HP. That doesn't mean they're worse, because the HP covers the entire ship, but you're wrong about how shields are better for mass and cost. 
