Sarries will be fine imo
Mako and Billy going would free up a lot of cap to use along with potential cap increase
I think the thing that set Sarries apart for so long was their culture which came from a whole cohort having grown up and played together for years plus some very well selected incomers who stayed for the long term. You can't buy that unity.
Just from the last Champions Cup winning 23 in 2019, Farrell's going, Kruis went, the Vunipolae will probably follow or are past their best, Goode and Maitland can't go on much longer. Barritt, Wiggles and Spencer went after staying a decade or so there. Long serving good club men like Wray and Barrington have also moved on.
That's not just a list of good players, but much of the conscience of the club.
Superstars like Skelton, Burger and Koch who were also in that match day squad went too. Add in other departures of solid players like Malins, Rhodes and Duncan Taylor and that's the heartbeat of the glory years gone.
We've already seen that many of their back ups aren't top class. I doubt they'll fall off the edge of a cliff, but there is a danger they might be 'just another club' for a while.
Itoje and George staying will be big for them.