Yes and No.
If Law existed in the crew from chapter 3 and Zoro joined later on, then yes he would be more popular.
If he came in the crew in the middle of series, then no he won't be popular because oda would change his style of writing around Law.
The only reason Law is so popular currently is because of the fact that he has more freedom due to not being in the crew. If Law was in the crew, Oda would write him just like bums on the crew and taking away his freedom.