The WAR totals don't account at all for playing time. Grisham has received about 430 extra plate appearances compared to Varsho, or something approaching a full season of play for these guys based on their typical playing time per season.
Average this out over 550 plate appearances, and Grisham has produced 2.45 FWAR/550 plate appearances. Varsho has produced an average of 3.16 FWAR/550 plate appearances. Each of these guys has an identical 96 wRC+ career value, however Varsho as mentioned has been a more effective defender. For what it's worth Varsho is projected by Steamer for 3.1 WAR in 2023, vs 2.1 for Grisham.