Edit: Seems Whiskey beat me to some of this already.
I neglected to mention that in in all this shuffle, we would also have to remove the ability to craft 25 str to accs to also match other jobs. ie: there would be a 125 net str gain on stock gear (which we already have by melding so not actually a large DPS increase. The only increase being 5 materia slots of secondary stats which is fairly minor all things considered). That essentially means that the 'swap' from left to right is 25 str less than youre projecting per piece.
With all the math done, the scaling from 350, 360, 370 would be like this:
(350 Current): (350 proposed)
(360 Current): (360 proposed)
(360 Current): (360 proposed)
Weapons:
315:268
330:278
347:291
Body/Legs
293:249
307:259
322:270
Head/Hands/Feet
180:153
189:159
198:166
Belts
135:115
142:120
149:125
Accs
68:115
68:120
69:125
All this does is really highlight how little progression there actually is because 5 slots have zero progression at all, so of course it looks bad when you even out the whole set. THIS IS THE PROBLEM. Tank progression is jacked. Tanks fundamentally have ~16% less str than melee dps in gear alone, but the same amount of secondary stats, so secondary stats have much more impact than str for tanks than DPS. Right now this is just entirely focused on pentamelded accessories, and if evenly distributed as above to match melees the power of secondaries is reduced on accessories, but increased on left side in direct porportion to the amount of str gained or lost, so yes, left side pentamelds would gain in relative power, but right side pentamelds would loose an equal amount of power. In this scenario the total number of primary and secondary stats remains completely unchanged, just where they come from.
All this stuff above is just the 'easiest' fix, but not neccessarily the best imo.
All that said, this is why I prefer the second option in which all primary and secondary stats are identical to DPS stats. This means a dramatic increase in overall str (accessories gain str= to dps accs), but you reduce the base weapon damage by a flat % to compensate.
For those uninitiated in the game damage formulas, Weapon damage is the foundation of all your damage and Str just multiplies that damage (which is then multiplied again by Det/Ten and then plug in crits/DH etc). So raw increases in strength are just a % multiplier in your overall damage and Weapon damage increases are also just a % multiplier to damage. We can increase one (str) and lower the other (weapon damage) and achieve identical damage output. So we can achieve even scaling like DPS accross all slots without any secondary stats overpowering ilvl by imitating DPS gear (raising our str and overall damage) then cutting weapon damage to maintain tank levels of DPS.
This gives more power to ilvl and less to secondary stats therefore pushing tank gear in the same direction as every other class. Ilvl is the most important stat. Raid drops superceed lower level pentamelds (Crafters survived when vit was primary, this wont kill them either as tank sales would just match other jobs crafted sales which still exist). Lowering weapon damage isnt an inherent problem. Brds have had lower weapon damage for the entire game. Mages magic damage is on an entirely different level of scaling all together. Books and staves have entirely different phy damage. Weapon damage makes no fundamental difference. It just sets the bar on how much damage a class does without changing the interactions of all the other stats in the game.
As for lowering the value of str (.9, .45, whatever) this also has negative consequences. The lower the ratio of str becomes, the more value the unchanged secondary stats become. This (in the extreme case) is why accessories are broken now. we gain so little str value (1 in 20 ilvls) that the increase in secondary stats is MORE important than the actual str gains and why the extra 72 secondary stats on pentamelds beat 20 ilvls of str. Lowering overall str values (like we have now) is the same thing as increasing the str number, but then lowering the str scaling. Both just make secondary stats more important.
However, if yuo raise the secondary stats to DPS levels (and therefore lower the value of secondary stats) ilvl reigns supreme. But to dial tank damage back, you cant just lower the value of str because that defeats the purpose of raising it in the 1st place. So you need to reduce tank damage in a way that doesnt affect str vs secondary stat relationship. Enter Weapon damage. It is a flat multiplier of ALL damage and doesnt discriminate. No side effects.
Raise str. Fixes progression, brings pentamelds in line where they should be. Reduce weapon damage to keep tank damage where it should be.