Interesting idea, but I think it’s not really needed. The idea about Hearthstone is to get more and more hearthlings, so you have enough military strength AND can cover all the jobs. This requires some planning from the player. I’m not sure if a job, that combines multiple jobs, fits into that idea. And when you have 50 hearthlings it wouldn’t be a great benefit to have one more hearthling. Lets not forget that the developers have to model/animate the architect and they need the code to enable him to do both jobs. It’s probably alot of work for something that is already covered by other jobs (carp/mason). I’d rather the them working on new content which gives the game more depth or increasing the performance further.
The problem with the job architect is: If you take pure logic into consideration, the architect must do something when it comes to buildings. Creating blueprints would be annoying, since it limits the player to create blueprints for selfmade buildings at the start of the game. Another idea was to let the player create 2 story structures. But then again, this would limit the player at the start of the game, which no one wants I guess. And simply giving a building speed buff wouldn’t be enough for an entire jobclass.