I'm not THF main job at all its just a utility-job for helping LS ppl get their stuff, so I for example didn't even know about the TH ticks being main hand / first hit only.
What I do know is I routinely hit th10 wearing TH0 gear, having landed TH7 on the opening hit. I'm not arguing with anyone or saying SE lied about about the TH gear spikes the %chance of further TH ticks, just saying you can use your regular melee/ws set and still build 10~ it happens to me all the time. If as I believe the TH ticks are percentile base chance, then haste gear gives you more hits including mainhand/first hits in shorter time, so I will stick with my haste set for THF and just use the TH macro at the start.
To be honest, rogue class, thief job, etc. were always about sleight of hand and deft touches, same as how on Earth a pickpocket will brush against you in the street, you wont see them and you wont feel anything except the merest nudge as they pass you, but when you get home your purse/wallet is gone. That always chimed for me with the TH gear that you swap in for one hit, it just seems more like the real world where truly pro thiefs will touch you just once briefly.