The boxscores can be a bit LOL... but a few things I've noticed are.
Minutes played, I've never seen a player with 20 minutes have a good stamina skill. Although you can get a 42 minute guy with Awful, inept stamina too I've seen... more minutes lends to a higher skill in that.
Fouls. 3 fouls in 20 minutes means this player is fouling every 6 2/3 minutes in this game. This can be a sign of poor defense, or poor stamina (he only played 20 minutes so I'd lean toward Stamina) but it could be both.
Free Throws. A lot like Stamina, going 4 for 4 or 4 for 5 doesn't tell much but a guy going 0 for 6 more is sign of a bad FT shooter.
TOs. A guy with a ton of them is usually always Inept or worse in Handling.
Position. This can tell a bit about their skills layout. a SG will usually have a good JR will a SF will usually have a good JS and okay skills inside.
I've been looking a SFs and you can get away with a 3 Ball one if you are building an all round one. I'd go with Player B in that instance. But if you want an Inside dominate one, Player A is a good prospect for that and will at least come with some JR then you'd just have to hope you have good OD and relatively good ID. But there is the risk with him being foul prone, but honestly that's a risk with all players, one game doesn't show much honestly.
My suggestion: take a gamble with Player A.