Well here's. My opinion.
First off, Pekka scales like this
37+ tons >> Giant (unphased by the feat) >> Pekka (oneshots).
So overall Pekka would scale closer to Mario. (If you want a better understanding, imagine the feat Senator Armstrong scales above in durability and then imagine a guy who could one-shot him)
Second, Pekka is pretty agile all in all. Have you seen the butterfly animation? That thing is cracked.
It also has a massive LS advantage so if Mario gets caught at any point he's doomed.
We don't know much about Pekka's skill sadly since we barely get any info on it but we do know it has basic swordfighting skills since it's created for combat as most troops are in the training barracks. Everytime you start training troops you "train" them and when they're created they already come out with great skills, archers and even bombers showing skills of extreme accuracy. Pekka is trained far longer than others so it probably gets to know the basics at least. The troops also stay in Stuff like this should extend to Pekka who is destructive even just by running around without the intention to fight. We also know it's durability scales above it's AP in durability as it's stated to be capable of absorbing even the mightiest blows which probably means other Pekkas.
Overall idrk.
We got Pekka's advantage of likely durability, LS, weight, destructive capacity
We got Mario's advantage of AP and Acrobatics.
Their skills aren't very comparable as they are weird to say the least. Both know basic combat skills but theirs are different on a fundamental level.
Mario has the acrobatics but Pekka has her speed equalized to him so Mario ain't gonna just casually evade everything.
Finally there's one more thing, Range. Pekka has a melee range advantage, a notable one. A single swing from it's sword will already cover several meters.
Meanwhile mario can damage it but not knock it down due to his weight disadvantage.
So overall i think i will give it to Pekka high-diff
