I nommed SWTOR and it's definitely a separate game from the KotOR games. There's basically no character crossover because of the time difference; I'd compare it to maybe the difference between Elder Scrolls games than the difference between Mass Effect games.

I also don't have much opinion on Dragon Age split or combined. I guess if it's likely to make the tagset hugely bloated, it would be better to separate them? Big tagsets can be harder to match.