Except TD isn't a good defender, he gets beat with bad rotations all the time. Like most of his game, the potential is there (I.E, his rookie year where he was an awesome defender), but he lacked real consistency since then.
I do think he and Monk are similar-ish players on offense though. Monk is a much better shooter and 2 years of positive upward growth of being an excellent offensive player. Both very explosive with their athleticism and have that "30 pt game at any time" sort of microwave streak. While TD is still trying to find that consistency from his rookie season and he's been very poor since then outside of that last 16 game stretch where he got hurt. Right now, it's not really all that close until TD can show that the 16 game stretch wasn't a fluke. His preseason has been a great sign he's ready to take off again though.