It would be if e.g. we got a 29 year old fullback with prem experience on 100k+ a week on a 5 year contract, theyre very useful for the next 12 months, then we're back to square one again once they start declining physically and we now have 100k less a week we can spend on another new fullback's wages because no one will take them off our hands.We've needed full backs for 5 years or more. I'm not sure how that would be a short term move.
I'm not saying those are the only two options...and I'd LOVE a good new right back...but you can easily make short term moves even in positions of great need.