Akainu would be dead, he is Lucky he never met Roger.
We already saw what Old, Stabbed, 200 bullets, 25 Cannonballs, inconaistent Haki, heart attacks Whitebeard did to him.
He left the Whitebeard battle altogether and waited for Whitebeard to die to come back up.
After taking Akainu, deathbeard proceeded to whoop blackbeards ass too.
Roger would be completely evaporated, if he already got stabbed to death by a weapon held by East Blue executioners.
We already saw what unrestricted, awakened Akainu did to Punk Hazard and the effect still remains the same even after 2 years later!!
We already saw what restricted base Akainu did to half of Whitebeard's face and beard in Marineford.
We already saw what Akainu did after coming back to surface, soloing whole Whitebeard commanders and Crocodile!!
Unless you actually believe these guys combined all together are weaker than Old sick 7% HP left Whitebeard.
So in that sense, Akainu came back after 2 sneak punches from Whitebeard, only to face even stronger foes!!
Meanwhile Whitebeard faced a whole team who ran away just after seeing Akainu, and still ended up dead...
He faced Akainu, the match somehow got paused, he faced weaker opponents who in the future chickened against Akainu, and still got killed lol