Yes, clearly. As I knew when I was going on holiday I could and would have bought both the OPR and Rover in advance.
First Great Western claim to allow on-line purchase of rovers, for postal delivery, but the website doesn't offer the rover in question.
I have no intention of looking through every TOC website to see if, tucked away in an obscure corner, there is a magic button leading me to a page where I can buy one. ATW advertise the rovers on their website, they are the principle operator of services on which the rover is valid, they should make them easy to buy!
Now, if I was actually allowed to buy a Rover more than three days in advance (say up to 12 weeks:roll

, then I could have easily arranged to pass by Stoke Station and buy it in person at the ticket office, hardly any inconvenience at all, but with only three days allowed that is much more difficult to arrange without going well out of my way and with extra expense of the local bus or train fare to get there.