Yeah he realized they could hide their powers, which is probably what let him know that power levels are bullshyt. Remember when he showed up to Namek he told Freeza and his goons that the radars are pointless. Yeah higher the "power levels" the bigger the attack, but its all relative. Like Gohan who had way power inside of him but could only let it out when he was mad. Thats why Gohan wasn't bodying nikkas as a kid cuz he didnt know how to fight.I haven't watched that DBZ in years but I thought he smashed the scouter because he had learned how to sense power level without one like the rest of the DBZ fighters already could
The higher the power levels the stonger the attacks and by magnitudes
With the androids they could absorb energy sure but only a certain amount at a time. Plus Dr Gero vastly underrated Super saiyans
I could be wrong though because again I haven't watched DBZ in a long ass time