Differing parenting styles

It seems like my husband and I have differing ideas on parenting. We have two daughters ages 3 and 5. Our older daughter's personality is more like my husband. Rambunctious, always on the go and a bit mischievous. Our younger daughter is more like me. Quiet, timid, and more stubborn. In my opinion my husband is harder on the little one and easier on the older. For example, he popped the younger one on the bottom for not getting out of the bathtub when he asked her to. But when the older one cut the streamers off her sister's brand new bike she got for Christmas he did nothing. In fact when I sent her to a time out, he let her out early. His reasoning is the younger was being "directly disobedient" while the older was just being "mischievous". I completely disagree. You can't pop a 3yo for not listening and then make excuses for a 5yo for tearing up her sister's stuff. I feel like you have to either punish both or neither. Am I wrong?