AHL team success and NHL prospect pools are two very different things.
Michael Sgarbossa and Michael Vecchione are the Bears' two leading regular season scorers. Neither of them is an NHL prospect. Outside of Vincent Iorio and maaaaybe Lucas Johansen, nobody on the defense has much of an NHL future. It's anchored by former NHL depth guys and career AHLers like Aaron Ness, Gabriel Carlsson, Logan Day, and Dylan McIlrath. Shane Gersich and Joe Snively are both 26 already. Ethen Frank, Beck Malenstyn, and Garrett Pilon are all 24. There's not much runway left for any of those guys left to take hold as even depth NHLers. There's really only three prospects that can be considered anywhere near Blue Chippers on the Bears (McMichael, Lapierre, and Protas) - and none of those guys would come close to topping out the prospect rankings on many other franchises.
And it's not like the Capitals have much in the way of reinforcements from Europe or juniors. Miro is obviously the most intriguing, but after that it gets barren quick.