Line infantry: 360 production (1440 gold).

Ranger: 380 production (1520 gold).

The line infantry has 65 CS and the Ranger 45(melee) and 60(ranged) with one-tile attack, the Ranger also has more mobility and do not cost niter.

What do you think? Imo the melee-type units are desing for being flexible and good at many situations and they never really get useless at during the whole game. The Recon-type units are focused on the world exploration(very useful), but the Ranger comes at a point where you would alredy have the majority of the world explored and even with that, exploration, combat, defense... there are other units that do the things better than a Ranger on when you unlock it.