I think the team can get at least the same production from Larnach and Wallner they are getting from Kepler and Gallo, though the defense may suffer a little.
The time is now to see if they can make the adjustments to stay with the big club, not after Gallo (this year) and Kepler (next season) are gone, that just delays finding replacements if they can't adjust.
Time for the FO to admit their mistake and move on.