That's certainly an annoying practice but I doubt it is actionable. That is, I doubt the Fair Credit Reporting Act, 15 U.S.C. 1681 et seq, or the court rules (whether state or federal) limit the number of times a document may be served. Unless it's more than a few times for each document, the debt collector can reasonably argue that it is only ensuring that you get the court papers. I can only advise you to validate that both copies are always the same, verbatim. You never know when the debt collector will make a subtle but material change on the 2nd version (the one being filed to the court) in a way that unduly portrays you as making an admission or false statement which you wouldn't actually make.
Do you know when the debt collector took the copy to the the sheriff office? At least with regard to the initial motion, it might have to do with the sheriff's delay. On one occasion I used the sheriff office services, and my complaint & summons was served upon the defendant two weeks later despite being located in the same small city (not Colorado). On another occasion I served a Personal Protection Order through the sheriff office. The PPO was served the next day but I wasn't getting copy of the proof of service. It turned out that the deputy mistakenly filed proof of service in another town.

