Ok similar question who do you rate better
Both players have 5 Star ratings and one is 18 with a 2 potential the other is 19 with a 3 potential.
Who do you take?
From those two I would pick the older one. I think that 2 potential could be starter potential at best, not so good.
What is the potentials are 3 and 4 does your answer change?
Yes, with those two potentials I would probably take the younger one with 3 than 19yrs. old with 4. 3 potential can be all-star and that is not that bad. You will have few more drafts before reaching top divisions anyway till then such a palyer should be ok for you. On the other hand if you picks for market profit 4 potential is a great bump in market value.
I would look at the boxscore too to see how much they could fit your already existing/planned training regime too. It could reveal some weakness you wouldn't your player to have a bit.