Varisian free-style fighter + Brawler staking

[Altar Father]

Hello fellow Pathfinders, first time here even though I've been playing for a few years now.
So my question is about stacking the martial flexibility class feature from the Brawler and the Varisian free-style fighter archetype.
Both get it from the get go and up to twenty without level or action cost modifications like in other archetypes that get the ability (like martial master) but nothing specifies any stacking affect (by stacking I meen adding the effective brawler levels).
So then the question is would it stack ? And further would you as GMs allow it to stack ?

[Derklord]

Per this FAQ, you'd have two seperate abilities, each with their own progression and uses per day.

As to whether I'd allow it, that depends on the rest of the party, and the character in question. I presume you're building a Brawler with three levels into VFSF for the dual stance, and delaying the early-access-style feats (e.g. Pummeling Charge) probably nerfs the character enough.

[Altar Father]

Thank you for your answer, the goal is indeed to have a brawler with the ability to mix multiple style without losing BAB.
I was right in thinking that it wasn't going to work RAW but having a positive return for home tweaking it will make things go smoother for the DM talk (if I ever get to play the character that is)