My experience in the cargo test game - the half-closed one, with just 25 players or so - is that it's insanely easy with so few players. I think the only base with 2 players was Heathrow. Everyone had profitability around 30%. It's good for testing new things, but it's not a real game with opposition. I had 700+ planes, nothing smaller than a MAX8, and no opposition on sight. 100 players and 200 planes? Well, everyone will simply play without opposition, and learn nothing about the game(which is, there are 3000 daily seats on this 1000 pax line - how do I survive & thrive?)
In current GW3, I've been attacked several times, had to adjust my strategies, replaces some 737 by 148s, lowered some prices, and that's what's fun. I've got even an opponent in Kansas City who annoys me with his E120, and takes my profitability down. There is no easy money. And it's the main interest of the game, IMHO. 100 players with 200 planes just means most lines will be unopposed.
Unless you want some games forbidden to players with too many achievements(but then people will do everything to avoid achievements, bummer.....)