Ferb:
Attack Potency: Wall level (
Threw a papier mache boulder with this much force)
Durability: Wall level
Powers and Abilities: Superhuman Intellect,
Superhuman Strength,
Broadway Force,
Pressure Points,
Vehicular Mastery,
Fourth Wall Awareness, Passive
Probability Manipulation (Ferb has a direct effect to probability itself, which makes
things skewed to go his way and end up right for him)
Ash:
Attack Potency: Wall level (Ran with and tossed a log much larger than himself several meters with ease. Took down steel bars with a tackle)
Durability: Building level (Has survived giant explosions and lightning bolts head on. Withstood an Aura Sphere from Riolu which could bring down metal doors)
Powers and Abilities: Superhuman Physical Characteristics, Extensive knowledge on Pokémon,
ColdResistance (Survived in a temperature so cold that his tear froze before it hit the ground)
Both of them have a plain Stamina rating of "High" & AP that comes from Lifting/Throwing feats. And Ferb has Class 50 to Ash's Class 10.
Class 10 is at most, 10,000 kg. Class 50 is AT LEAST 25,000. (Also, why Ash is Class 10 when it begins at 5000 kg, & his feat is 999.9 kg effortlessly is beyond me.)
So Ferb is probably 2.5 times stronger, more or less.
Given all that, it seems likely Ferb has higher AP.
Also, he's tied in stamina & range, vastly smarter, can use pressure points to try to incapacitate Ash, Broadway Force (Break into a musical to control the situation.), & Passive Probability Manipulation that makes things always go right for him.
The only thing that makes me question if this isn't a stomp is Ash's Building Level Durability, & even them, Ferb's LS can thwart it. Can you choke someone with higher durability? What about just covering their mouth & nose? Bury Ash more than he can lift? Get him to water & drown him?
Point is, even if Ash has higher durability, Ferb still has way better hax, smarts, & his Lifting Strength gives him several win conditions. (I know why, but IMHO, it's laughable that "LS" isn't important in Vs Matches.)