From the Prologue of TGS he comments he has a lot of boys and old men, basically roping in every male on two legs he can. The borderlanders explicitly comment they've left strong armies still behind. That's still probably unrealistic, but at least not pretending Arad Doman can pull 100k experienced soldiers out of their rear.

Though I don't remember it explicitly stating one of the armies is Rand's. It's ambiguous.