Before I start my review, you cannot put in the map category both "Melee" and "Altered Melee". It's either the former or the latter.
Ok, now let's get to my review:
The terrain looks great and was well done, though it has some resemblance with Full Scale Assault. Did you use that map as a base? Don't worry, if you say yes, there will be no problems

It's just that if you did not do the terrain completely, I won't bother myself judging it as Blizzard would be its main creator.
Gameplay-wise, your map does not offer something really original or different from Blizzard's normal game. The only thing that makes this map different from a common melee map is the presence of 4 custom heroes, These are not enough to make a decent difference. Despite that, I tried them all and I must say all of them are pretty overpowered. The passive Whirling Strike of Warlord can literally sweep clear entire armies because it has a large area of effect and can even damage air units. His ultimate, which is supposed to be able to be learnt at level 6, not 10, is too unbalanced, considering the high HP regeneration he has.
About Mage Slayer, he can burn all your mana in a few seconds. Mana Hungerness makes him attack so rapidly as though he were crazy so Feedback keeps burning mana as an excessively fast rate. You do not appear to be familiar with the Object Editor. If you type 2.00 in
Data - Attack Speed Increase, you don't make the AS increase by 2.00% but by
200%!!! This means that at level 1, Mage Slayer can triple his attack speed!! Let's not forget about Ensnare then in case the hero decides to retreat. Add to that his permanent invisibility at level 6 and you basically force the enemy to play with heroes with very little to no mana.
Nature's Guardian Demolishing Seal is just inappropriate for a normal game. Due to its low mana cost and high damage, I can get rid of enemy buildings, especially towers, without even getting close to them. Enchanted Orb could use of some nerfing because Nature's Guardian has a big mana pool so he could annihilate a weak enemy hero with 3-4 attacks. Just bring with him some mana potions and he is destructive.
Admiral's Deep Slash is extremely unbalanced. At level 1, it slows down movement speed by 50% and attack speed by 25% which is unacceptable. What is even worse is that at level 3, movement speed is reduced by 100%!! That's nearly the equivalent of a stun! The stacking damage also makes him very very deadly.
There's also something I don't get. Why are the guilds (taverns) guarded so heavily? You put 6 level 10 heroes in front of them, causing any attack to them to be a suicide, even in late game. That just hinders me from hiring heroes from the guilds. Normally, taverns shouldn't even be guarded to allow players to hire a tavern hero as their first hero. If you make it impossible to hire tavern heroes, your map breaks down to a very common melee map, nothing more. I think you should just make this map a simple melee map without custom heroes.
As for now, it is moved to
Substandard/Too Simple.