Lack of short term IR

So, it’s all been beaten to death (and we have so many problems, this one may seem insignificant) but one thing that perplexes me more than anything with this front office and coaching staff is our inability or unwillingness to use short term IR. From Michael
Thomas (prior to real IR), Jarvis Landry and now Marshon Lattimore it is just perplexing. It’s caused us to loose a player like Murry (which is hurting more now with Ingram down). Am I missing something?
There is no such thing as short and/or long term IR! There is just the IR list and you can't be activated until you've been on it for 4 weeks. That's it. How is it that a 2nd person got this wrong?