I don"' tunterstand why you put the mission 4 after the mission 5, but,well, I just tried it. Indeed, it was very easy, maybe too easy...
We have a little army against a little castle. So, instead of building a castle like in the other maps, we must here attack a castle. However, I don't unterstand why you give so much gold to the engineers. We can do trebuchets, so we can destroy all the towers quite easily, and killing with the macemen the troops. There's no interest to play on this map, the siege is quite boring. Well, I don't use the trebuchets, I send my troops without using the engineers. In this case, the game was very more pleasant (it's the reason which explain why I give you three points for the playability). Can I suggest you to edit your map bu deleting the engineers, who aren't very useful in this map ? Without them, the game is more intense, we have to use simultaneously all our troops to win.
The only thing I have to say about this map is : "Too easy"... Really... All the macemen come at the beginning, so we just have to kill the crossbows and the archers. I don't want to repeat myself, but the problem of the difficulty is the same problem with the playability : because we can use a lot of trebuchets, the siege is too easy toi be a good siege. In a word, it's very too easy to win.
Comparing to your other maps, this is the first siege, so you win some points. Yet, the siege isn't very original, so I can't give you a lot of points. We don't have to create a great strategy to kill all the enemies. Well, it's very too easy,and sometimes, a map which is too easy is a bad map. It's the case here.
Map Design: 4
Well, the only good point here. There's a lot of mountains put in some place, giving a good impression (I like the mountains xD) of a natural place. In a way, the design of the map, the architecture of the castle, makes me think to the mission #12 of the military campaign of the game, where we must take a castle and develop it against the Snake. There's something like that (about the design, I mean) in your map.
The same thing as for mission 5, or mission 3, or the others missions... A short scenario, not developed, so not very interesting.
Well, I don't like to write bad reviews, but, well, I must admit it's a bad map. But, well, don't discourage yourself, the better way to progress is to be criticized. I think you must list read again what Arfomath said youin the Topic of the mission #5 : like him, I think it's better for a mappeur to insist about the quality than the quantity... Don't hesitate to test carefully your own maps, to analyse where are the defaults, the qualities, things like that... I'm sure you can do a lot of goods maps.