Structures Built - Is This Possible?

Hello there, guys! You see, I was trying to make a melee-like map with peasants and all, but I have a little problem. I wanted to give the peasants 12 structures from which to choose to build, but the game only shows 11 of those because of lack of space in the Buildings menu. Is there any way to circumvent this? I'm not against giving the peasants another build button, a la Starcraft's and Warcraft II's "Advanced Buildings", but I have no clue on how I could do that. Any ideas?

spell book with build spells
replace peon
or may be add convertable buildings, like human tower.

But I want the structures to be built like normal structures. If I place build spells, they will auto build like Ivory Tower in normal maps, right?

About the convertable buildings... I don't quite think it is an option... It would screw up what I have planned for the map...

I think this might be the best option. When the player clicks the "advanced buildings" button, switch the peon out with a special one who has all the advanced buildings, then open the new peon's build-menu.

Oh! I think I now understand what you're saying! But, how could I do that? Scripting? I'm a complete dummy in this kind of stuff :/

Its easy to do with triggers, in the trigger editor, just give the unit chaos ability, with the end unit being the advanced unit. (or use the 'replace unit' action, ive never used this so i dont know exaclty how it works, but it seems suited to this situation)

try make it on your own, then post how far you got for people to help you

In Power Towers I used the bear transform ability to add an alternate builder. You just need to remember to also include all alternate buildings in the main builder (at the end of the list so they don't show) or the alternate won't be able to build them.

make the builders upgradeable, the advanced builder can only build advanced buildings, and maybe has gathering bonuses or something. wouldn't require triggers either.