- The equal of the Reach? No. Even at its full potential, the Riverlands can raise 45,000 men and the Reach has 100,000.
- The equal of the Kingdom of the Rock or the Storm Kingdom pre-Aegon? Yes.
- Having a coast on the eastern side of Westeros would help, assuming the Kings of the River worked to develop Maidenpool and Saltpans.
- I think the Reach’s fundamentals were too strong to really prevent it from becoming a great power, but perhaps some of its wilder expansionist phases would have been limited.