What is the difference between talent and talents?
These scientists have great talents
These scientists have great talent
These players have great talents
These players have great talent
The singular refers to talent in general; the plural invites you list the specific talents you have in mind when you say this.
I would say, "the players are very talented." When I say, "They have many talents" then I must start listing them (they are poised, balanced, responsive, or whatever)
To say "The artist has a great talent" is simply emphasizing that you think he's a very talented artist (as an artist; not necessarily as a basketball player).