No. 8 shot is a more than useful shot size for Sporting and some very good shots use nothing else to great effect.
I wouldn’t feel entirely confident being restricted to 9 shot – or smaller – because it can be found a little short of clout where long-range edge-on clays are concerned.
That said, the extra pellets you get with 9 shot do help fill the pattern and the ‘kills’ on clays out to 30 yards or so can be quite satisfying – especially if the target is showing some of its vulnerable belly, not just the rim.
The only way for you to answer your own question of course is to get out on a shoot or two and use these shells yourself.
I think you will be surprised just how well they perform over short to medium distances, but be prepared to use something a little larger when circumstances demand it.