As we discussed in Discord I think all races should be able to be all classes.
BUT IF NOT
Then everything but Paladins and Priests, and maybe, just maybe not Druids.
I'm not sure about Druids because I would like to see an ORC DRUID, nature is dangerous, Orcs still have that primal sense of measuring strength through fights, and Orcs have learned to survive dangerous places.
If you want sell a DLC that allow us to play all classes with all races, but I would really like to play any class with any race, TAKE ALL MY MONEY,
I absolutely agree with the desire to have all classes available to all races. There is no benefit to restricting race/class combinations. It doesn't make your choice of race or class more special or important, it simply limits your choices. As a somewhat extreme example; when I used to play WoW, I only played Orcs. They were my favorite race and as much as I liked the rest of the races being available and present in the world, I was only interested in playing Orcs. This meant there were classes that I just didn't ever play. While I admit this is a self-inflicted restriction, there wasn't any benefit to me to make up for the inability to play certain classes. Being an Orc shaman isn't any more special than being a Dwarf shaman, and the fact that Gnomes can't be Shamans doesn't make it any more interesting or desirable a choice either.
I like the intention of Scars of Honor, I like the very familiar and stylized art style, and I like the selection of races and classes you've presented so far. As big a fan of Orcs as I am, I would likely do the same thing in SoH as I did in WoW; that is only play Orcs. However, my favorite fantasy RPG class is the necromancer, and you currently aren't allowing Orcs to be necromancers; meaning I would likely choose not to play Scars of Honor simply for the fact that you have made the decision that I have to choose between playing my favorite race OR my favorite class fantasy.
This race/class restriction concept is a holdover from the early days of tabletop RPGs, as far back as when Elf was a class in D&D. None of the major tabletop RPGs have restricted race/class combinations in decades. Other MMOs are even starting to move away from the concept. WoW keeps opening up their restrictions to the point that the ones that are left make less and less sense (outside of requiring some unique art assets), FFXIV allows you to level every job (class) on a single character; GW2 has no race/class restrictions; etc.
In our modern gaming culture, my opinion is that race/class restrictions are a dated concept that does more to diminish interest in your game than it does to provide your players with an enjoyable experience.