Nice idea for a themed map. While having different merc camps in different parts would not be good for a ladder map, for a "fun" map it is acceptable and fits well too.
Making such a large map is a lot of work, and therefore not everything is polished, which is understandable. Here's what I think should be improved nevertheless:
1. Mercs at the northwestern Lordaearon Summer merc camps can be stuck if bought (Troll Berserker, Ogre Mauler).
2. The creeps at the starting locations need antiair defense.
3. Creeps defending gold mines should not blue. Every other creep should be blue.
4. Some itemdrops are too strong/weak compared to the strenght of the creepcamp. Example: The 3 lvl 6 lizards only dropping a lvl 2 item, the 5-2-2 ogre-troll spot only droppping a single lvl 1 item, the rogues/wizards at the more central merc camps only dropping a lvl 2 item.
5. Pure flying creepspots are very annoying for melee-based armies to creep.
Obviously, the point about trees from your other maps applies once again. Still, I think you should at least fix 1, 2 and 3 to provide a bug-free map. Map set to Awaiting Update.