So I always liked the Tortles from the Savage Coast setting and I'm thinking of doing them as beastmen. I'm still working it out but I'm thinking that a religious movement has sparked an alignment shift in some populations of turtle people, while still beastmen then are neutral-lawful. I was wondering though, would changing their attack roll bonus per racial value with a hitpoint bonus instead break things? As in I remove that and have their value stack with Hit Dice adding the hit dice XP per value to their base 0 value xp cost. Also what if a given class does not allow both the divine and arcane mystic paths? Like if there is a class with the option to become a witch doctor but not a shaman, or vice versa.
Attack throw vs HP: Is what you're wanting to do is have the racial bonus from Tortle stack with the HD value rather than the Fighting value?
My guess is "probably not", since Fighting and HD values have the same XP progression, and they're both capped at a maximum value of "4". If you uncap it (d12 hp, d16 hp, d18 hp, whatever) there lies potential craziness.
Mystic Paths: I think what you'd do in that case is reduce the Racial XP value accordingly.
This old post http://www.autarch.co/forum/gnomish-infravision-0 details some of the math behind that.
Without going through and deconstructing the whole race (or any of the beastmen) based on that post, if the "Path" options are worth a power each, it's probably worth about 50-75XP off the racial XP value; 100-150XP if each one is worth 2 powers.
I'm kinda leaning towards 1 power in worth, but that's just me.
I should have read the entire article before I worried about it, I could just do some vairant of the Bugbears Battleborn ability to toughen them up, no stacking with HP necessary. Also I suppose it wouldn't be a huge deal to allow both mystic paths since if I made a Tortle Padre that had a 1 or 2 in divine then the option to take the Witch Doctor path would just let you get some more spells while staying primarily a divine caster.
I really should have posted this in Ask the Autarchs, because I'd love to see a breakdown of the XP values for the various beastmen classes. The gnome one helps, but I'm still not exactly sure how some of the bugbears abilities are valued.