not really. Suborbital vehicles achieve orbital heights. It's actually probably easier since you don't need a payload. The velocity alone will do the trick.

Nah, they are pretty similar in difficulty for interception - the first US ASAT program used essentially the same Nike Zeus missiles used for ABM duty during the late 50s

Except you don't. You only need to match velocities if you want to dock with something.

Hitting something in orbit just requires you to be in the way at the right time.

Basically an intercept is a lot easier.