Is it possible to schedule certain systems after others

[neat tendon]

Yeah, Like this:

.add_system(sum_velocity)
.add_system(clamp_velocity.after(sum_velocity))

[verbal yacht]

Beware, any commands applied won't be available in the same stage unless manual apply_buffers is called.

(ie. if you add/remove components, resources, you'll be waiting for the next frame to be able to detect the change/use the entity or resource) unless you apply the changes to the world