Knowing Rivera, I sure don't. Ron Rivera is regarded as one of the best coaches in the league and truly one of those guys who sees the game above the rest. Zimmer is still somewhat unproven and much more in the postseason.
McVay is good, but you said yourself coaching is what the league is and he hasn't coached a playoff game.
Chargers would beat Jags and only because Ingram and Bosa would give Bortles nightmares.