In a sensible village build (without churches) you would be looking to have around 20k troop spaces. I think my usual village build of 10k points used just over 3.7k population. It is always advised to max out your Barracks and stables so you can rebuild troops quickly, and whilst many players will keep their workshop between level 2 and 5, I tend to go higher in order to create a standard point level of 10k per village. This means that especially when I play church worlds I can adjust my builds slightly to factor in a church into the 10k build, making it less obvious as to where the churches are. Too often players forget about that, and when you look at their village list you see a little spike in points of villages with churches, making it easy for the attacker to target the church villages first, resulting in fewer losses in the long run when attacking all the other villages.
As to the barracks/stable issue, it is not something that I have tested myself, however it could be that you need the barracks at a certain level to have the stable function, as the Academy doesn't work without the Smithy at level 20.
It has been several months since I last played TW though, so my memory could be a bit hazy. If you are interested in looking at some troop builds then I think I still have my excel sheets with my world setups somewhere.
