There is discussion whether to have more barracks and less houses or more houses and less barracks.  I decided to put it to a test.  Town had 5 L19 barracks and 9 L17 houses.  I checked how long it would take to train 4500 Tier 1 troops with the 5 barracks.  I used 4500 as that was the maximum that 4 barracks could do at L19.

I then replaced one barrack with a L17 house and checked the time needed to train the same number of troops. The time savings was a meager 6% of the duration.  This doesn't make sense as each house is supposedly giving 1% per level speed increase, i.e. duration reduction.  The time savings should have been around 17% I would think.