The Nats entire draft looks to be setup to sign the top 3 picks. Crews may not take less than slot and both Morales and Sykora probably dropped because of bonus demands.
Interesting all-in strategy for a rebuilding team though I guess you do whatever it takes to sign Crews and later maybe think of flipping an outfield prospect for a pitcher (they have 4 good outfield prospects now - potentially all top 100 unless Hassell drops out of it).