They lost Tony and Manu and replaced them with DeRozan and White. Walker doesn't count, because he's going to play just as much as White (whom you didn't count for last year) did last season. Anderson at least cancels out Beli. Moreover, last year, the team had offensive issues without Kawhi, so merely replacing that output isn't good enough. The offense would have been fine had they had Leonard's scoring and gravity, but this year's team won't get that. When you lose as much D as they did, you can't just tread water offensively.
Even so, last year, the team had White and Murray as PGs behind Parker and Manu. Murray started because Tony was still hurt, but they still had the depth to take two injuries. Now we're expecting every one of the "facilitators" to be in the rotation. If one of them goes down, they aren't being replaced by Murray or White. They are being replaced by Forbes, Pondexter or Cunningham.