Nah that's 100% fake
Let's say an item is doing 20 to 40 damage as an example
The item being ethereal it now does 30 to 60 damage
Let's consider that in both case the items has 300ed on it and your char without the weapon has +1000% off weapon enhanced damage
The damage of the wepaon will be then: 120 to 240
The overall zeal damage is 1320 to 2640
1) if it has +15max the overall damage of the item will be 120 to 255 pumping the zeal damage to 1320 to 2805
2) if it has +25 Str the overall damage of the weapon IS NOT changed it's still 120 to 240 but then the total %ed is boosted by 25str (which is about a 1.2 ed per Str smthg like that for hammers). Considering you don't use that strenght to put into life and you really use it on top of your 220+ Str for armor it will add, let's say 30ed so you have 1030%ed so the zeal damage will be ~ 1360 to 2820
This is how it works
But here the example i typed it from my head so the results aren't the best lol, but 288+15max is much much much better than 270+str
You usually have more than 1000ed so the 15max is directly multiplied by all the ed
While 26 Str will only act similar to a jewel off weapon adding about 30ed on top of the 2000+ that you already have
Tldr; on a weapon max is always better than str (ofc do not compare +2max to +30str)
Tldr; the higher the base ed the higher your damage, whatever adds there is 288 >>>> 270