Why are people complaining? The only players on the roster who can physically guard the elite or even second tier combo forwards, is the starting SF (whether it ends up being Leonard, Covington, Anunoby, etc.) and Gay. Even if you prefer the latter do so, this at least throws another body in the mix. And Walker was already ticketed to spend most of the season in the G-League.
As an aside, it's probably another sign that Ginobili is retiring (even though his words seem to indicate otherwise). Too many rotation players and a Leonard trade is unlikely to alleviate that.