In that particular move order I'd suggest 4. Nc3. It's avoided a similar position where black equalizes easily (1. c4 e5 2. Nc3 Nf6 3. g3 Bb4) due to Nc6 not having been played.

I've always felt white has a small pull when he gets to play e3/Ne2 against Bc5, and his Nd5 plan is plenty effective against Bb4 in that move order. I'm not aware of anything special black has in the line Kosten gives, but maybe Marin mentions why he chose 4. Nf3 instead.

White doesn't have much in the line zoo gives.

There's some factors in white's favor that makes me think he might have a very small edge (space, pawn structure), but the b3 pawn nearly negates all of that, given it's on a light square, advancing it eliminates one of black's pawn islands, and defending it isn't easy.

Sunday I played this game with White, and found later in Marin’s book that White is better after :
1.c4 e5 2.g3 Nf6 3.Bg2 Nc6 4.Nf3 Bc5 5.0-0 d6 6.Nc3 0-0 7.d3 h6 8.a3 a5 9.b3 Re8 10.Bb2 Bf5
11.e3 Qd7 12.Nd5 NxN 13.cxN Ne7 14.d4 exd4
15.Nxd4 Bh3 and  now Marin says : 16.Qf3!? and White is better, if Bg4 then 16.Qe4!
What do you think of this judgment ?

In the game i played :
14.e4?! Bh3
15.d4    exd4
16.Bxd4 Bxg2
17.Kxg2  Ng6 = or maybe slightly =+