Just looking at something real quick. These are minutes from last year of the departed & I'll use WS as the relevant stat because it's easy:
Grant 2,045, 4.4
Smart 1,957, 3.7
Brogdon 1,744, 5.8
Timelord 824, 3.8
Blake 569, 1.8
Muscala 323, 0.8
Vonleh 171, 0.2
JJax 107, 0.1
Champagnie 23, -0.1
So they need to replace 9 players totaling 7,763 minutes & 20.5 Wins (0.127 WS/48).
& they have brought in...
Jrue 2,183, 6.7
Staps 2,102, 7.7
Stevens 1,120, 1.9
Brissett 1,083, 1.1
Gabriel 1,024, 2.8
Svi 468, 0.8
Banton 279, 0.4
Scrubb 30, 0.1
Queta 29, 0.1
So 9 players totaling 8,318 minutes & 21.6 Wins (0.125 WS/48). Plus Jordan Walsh.
So beyond the obvious improvements to a closing 5 lineup, it seems like they aren't really in a much worse situation for the regular season in terms of overall talent & ability to replace the minutes lost. This of course doesn't factor in things like different injury luck for the players they already had & internal improvement/unimprovement, but there are plenty of new bodies capable of playing potentially competent NBA minutes in depth roles.