Sure I forgot that languages come from race and background (meaning it has nothing to do with any feature group). Its not uncommon for me to use a flawed example. I don't agree that the overall point is diminished, concept of classes being feature groups and that building off a feature group that is counter to the stated goal is not a good place to start. Their are multiple other feature groups that are strength based and far better starting points for achieving the stated goals.There is nothing at all that says Feature Group #1 typically can't read. Not in any 5e book. They can speak, read, and write in any languages they have proficiency in just like any other Feature group.
You weaken your argument with falsehoods.
If its your intent to target my creditability over a minor inaccuracy while ignoring the strength of the stated point, then the ability to be heard and make a point is by far more diminished by the listeners desire for "me to be wrong" rather than have a discussion and consider that points being made own their own merit. I get what your saying and I get for some readers they will write me off for one mistake. I highlighted you doing the same thing, however, your point that people will ignore me for being inaccurate is true only for those who are primarily looking for any reason other than my argument to invalidate the point. So your not wrong in regard to people who are hear to argue but its my hope that the OP who came here to ask opinions, was asking for actual constructive input instead of placating moral support in affirmation that they had done a great job. That in mind I don't necessarily expect the OP to read and agree but I would expect the OP to focus in on the point and consider its merit.
In this case I really like the idea of the subclass and the majority of the features but I think the goals of the stated end result, is greatly hindered by the choice of starting point being apparently picked not by its mechanical design but the name and implied role it provokes. If I was going to make a thug, I might have originally looked at the class features of a class call "rogue" as well. Having looked at those features and read the posts by the OP, I feel like his (and my) original instinct leads to a contradiction through meta names that don't really matter in play. If the OP sees that and understands, then decides to do it anyway... the appears what they said the goal was is either not true or has evolved as a mater of input. For example, they may want to make a subclass using the feature set of the rogue specifically but what to use strength because their GM uses variant encumbrance and having strength for attack, armor, encumbrance, and grapple mechanics makes it the god stat... the alternate solution then is to give the Dex rogue a bonus to encumbrance and grappling which then allows it to be a rogue play as a rogue but fill the new goals that were not previously stated. But I don't know that without being sure the OP understands my point and the OP being striate with if this reveals a they had goals they didn't realize and had not previously stated. Maybe we will see. I hope so.