2...Nc6 is a double van geet. Black responds to Nc3 with symmetry. With d4 d5, one can enter a closed opening. Yes, in closed openings it is bad to block the c2-pawn (c7), but since it is blocked for both White and Black, the game is equal. e4 e5 tranposes to the Max Lenge Defense. Nf3 is a very flexible continuation. The game can continue: 2. e4, 2. d4, 2. Nf3, 2.b3, 2...g3. e3 and d3 seem passive at first glance, but this is not so. There is also the move b3, also normal. g3 is normal too.

Theory table