Alter, replace and modify

[Shodaw]

Due this FAQ, the altered/replaced class abilities for one class shall not stack with the same altered/replaced class abilities from another archetype, however, there are some more rare seen class ability alterations, such as "modify".

Bloody-Knuckled Rowdy bloodrager archetype wrote:

Reduced Spells Known: The bloody-knuckled rowdy focuses more on fighting tactics and less on his natural arcane powers. He receives one fewer spell known at each spell level. This ability modifies bloodrager spellcasting.

So the "modify" was considered as the same catalog as class abilities been "altered" or "replaced", or they are out of this alteration loop and will not prevent the archetype stacks?

[Drahliana Moonrunner]

If an archetype does ANYTHING with a class feature, that counts as modify. You do realise that alter and modify are practically the same word?

There is no legal way to stack multiple archetypes that do anything to the same class feature.