Walkthroughs for custom maps.

Taking this opportunity, I'd like to ask about "Wayfarer": I saw a video where a player defeats an antimagic garrison with 4 stacks of megadragons, each with 9999 units. What impressed me most was the time: the 70th month! So, is this map really that long to complete, or did the guy just want to defeat this garrison out of boredom, accumulating troops for several in-game years? Because, as I understand it, this garrison, like similar ones later on, is just there to "challenge" the player, and it's not necessary to defeat them. By the way, after this garrison, there's a sign with the name and contact information of the map's author:

Map maker Ustcers, Foward Chen, Tiger

I'm currently playing this map, and so far I'm enjoying it, but I'm hoping for a reasonable completion time: I really don't like drawn-out stories. In general, how long did it take those who completed it? If there were such data somewhere, I don't remember now (I'll search the forum).