Yea, that can be tough, hope the roundup took well....
I'd make one disk pass a 1/2 day after plowing, so the slightly damp lumps bust up yet.
I would plow, wait for a rain to mellow the ground, and then disk it after the rain.
Depends on if you need to be in a hurry or can wait.
In my soil, my climate, worst is if you plow, wait 2-3 days for the lumps to dry out & turn to bricks, and _then_ try to disk it.
Actually, I used to plow, run the harrow over the field in the same direction I plowed it within 8 hours, and then disk it the following day. This got the lumps dealt with somewhat, hoped for a light rain in the next week, and could work up the seedbed nice after that.
Bottom line is, best to work it while the plowed lumps still have some moisture in them, whether fresh from plowing or after a rain.