Sub builds are pretty trash for leveling, but it’s the build I used all the way to like 35ish because I was a noob, did very little damage lol. But I had fun with it for a while, I guess?
The only thing that sucks about Combat is that you’re going to be competing with Fury Warriors, other Rogues, and plate tanks for the slowest 1 Handers that you really need to get the most out of Sinister Strike, such as Dal Rend swords, I think one of them is for Rogues but good friggin luck trying to get one over the tank threatening to drop the raid over it, they’ll pick someone else over you every single time.
And, ideally you’d want a fast offhand to proc Combat Potency as often as possible, like with a dagger, and really getting daggers won’t be a problem for you at endgame, but you’ll rarely have the “good” setup till you actually get the blue/purple drop you needed.
So, in the meantime like with leveling, you end up just using the slowest thing you have in your main hand and the fastest thing you can get in your offhand, which may not be very good. It’s one of those things where weapon speed really really matters even at mid level range where you’re getting into Combat Potency and need that energy to fire off Sinister Strikes.
That’s pretty much the only annoying thing about Combat besides the pre-Combat Potency energy starvation, which can be partially treated with Thistle Tea.
However, if you’re going to be doing a lot of dungeons you might have a good time with Assassination, I honestly forget how it did for leveling, I know Combat was pretty much king of leveling, but ‘Sin had some sort of “keep on killing” mechanic/talent that helped with your uptime. I think?
TLDR; I would go Assassination till around 30-35, then respec into Combat and go get the Thrash Blade from the quest in (Desolace?)