When they both retire no one will hand pick certain stats to make one look better than the other.. They will look at their overall stats in which currently Messi has a better game to goal ratio in the CL.
Also worth a mention...
Messi 775 games 627 goals
Ronaldo 923 games 661 goals
Messi is only 34 goals behind the so called greatest scorer of all time.... in 148 less games AND 2 and a half years younger
Take pens out the equation as well and he'll be ahead.
It's like his Portugal record. He'll probably go on to score 100 goals but he's already on 154 caps and will be pushing 200 over the next few years which nobody has ever done before. Not to mention the amount of weak teams in European qualifiers.