User blog comment:Choocolatiah/Minimising Gem Expenditures/@comment-2607:FEA8:33E0:1A0:F8F8:8569:DE44:4A8D-20190102053622/@comment-25435121-20190102185639

you would lose the "max level" bonus of 5% plus 5% of the soldier difference between level 89 and 90. For President Calamity, the soldier count at level 89 and 90 should be the same, so it would just be 5% of 49999 which is about 2500 soldiers off.