The Reach would have had a serious boom in population. It's Malthusian Dynamics (choose to believe them or not, I have my issues with it), more food, more people, it means that even if there were surpluses, more people are born to basically either use that grain or make more. It's weird to explain it in full, but TLDR, the Reach should be booming in population, especially with the stability that is there. Though I would imagine that while I would be tempted to say that their armies would be bigger, the only reason they aren't is due to peace. In every other Kingdom, there has been war, civil and with little disputes, the rebuililding or creation of houses being responsible. In the Reach? That hasn't happened.
Plus Garland is being a bastard-making machine. Well, he hasn't gotten any hate mail/boxes with babies inside yet, I can imagine that he is basically seen as being this kind of fellow that Reachwomen find really dashing. Hey, it's Flowering Season in the Reach :P ...that is such a terrible joke, I don't even know if I should make it. None have come back, it's kinda like they're humbled to have sex with you know, their handsome young Lord...
(I should say, if you are displeased or dislike Garland's behaviour, go down to your local Nightclub. Hey, I speak what I see :D )
@bluetommy2The Rose has thorns. It may be the heart of Chivalry, but remember, with people like Alerie, she is the Rose of Thorns. They have honour, but remember, it is to themselves, to their people, and nobody else. They are playing the game as much as anyone else, and while they know it's a big ask, they are basically going to do what they will, quietly and with the most careful dictation that they can. They are charitable, kind, brave and good noble people, they really are, but underneath that, you find people who are driven to protect their own, protect those who ought to be worthy of their protection, and fuck everyone else.