Is it impossible for prior service to join a Ranger Regiment?

SGT (Join to see) I defer to SFC (Join to see) , but if you can meet the standards, why would a prior service soldier not be able to? When you think about it, everyone going to Regiment is prior service. A 42 year old Master Sergeant just graduated from Ranger School...granted he was a long tabber , but 42 years old just the same.

https://www.goarmy.com/ranger/join-the-rangers/requirements-to-join.html

No one cares what branch you come from, or what service component. While I was in Ranger regiment we had plenty of prior service and former Marines.
If you are not eligible to receive an option 40 contract when you switch services, you can ask for Airborne School and volunteer there. If you can't go to Airborne School, once you get to your first Duty station you can volunteer then

TLDR; I’m trying to do the same thing, from what I’ve learned is you can get Option 40 but only if you aren’t MOS qualified for the slot you want. That’s assuming they have them available, your best bet might be to try when the fiscal year restarts but honestly it seems like luck of the draw.

I’m in the same boat (sort of) I’m prior service (11B) trying to find a way into regiment myself. Honestly I haven’t found any sort of answer that makes any sense, I called 75th recruiting and they said Op40 is available to prior service and so does AR 601-210 Regular Army and Reserve Component Enlistment Program. According to the Prior Service Business Rules anyone with 48 months or less of Active Federal Service should be exempt from the rules and be authorized Training of Choice. The issue you’ll run into is at MEPS, the counselor (in my case) said the opposite of what Ranger Recruiting said. “NO OP40 Prior Service”. The counselor for some reason seemed to think Option 40 sent you to Ranger School? He basically told me “Why the fuck do you wanna be a Ranger? Anyone can go to that school.” Which worries me, because he’s not even sure of what the Option actually is that he is denying you. If you don’t run into issues like that you should be okay IF they have the slots. The counselor did offer me 13F Op40 before deciding I couldn’t have it because I was colorblind...(I’m not, I had literally just finished the airborne phys and Doc signed off on it).