^Nice pointers from Remixer
1.) If you're making a map, be sure to make early creep camps are grounded otherwise putting harpies for example could be a real disadvantage for Undead players since they have to reach Tier 2 to gain Web ability for Crypt Fiends.
2.) This is a very basic yet often mistake for melee map makers. If you're an extremely competitive map, USE Blizzard cliffs; it will be a huge game changer as sight from units below are degraded and gives most upper advantage from units above, this way it makes the map entirely more tactical.
3.) I think Orcs and Night Elves needed lumber the most and among the 4, they're the ones who seem to gather the lumber slowest. For Orcs, they need them to sustain high tier upgrades while Night Elves, even the basic ones need lumber. Just thought worth mentioning that if I were playing either of the races, I would rush for Goblin Shredders.