That's just like my two. S4 has always had a penchant for trouble. The second he learned to walk he became our trouble-maker. I used to call him my "little monkey" because those hands of his were always getting into something, grabbing things off a counter top in a flash.
The difference in our case is that although S8 seems more the rule-follower, he too has his cantankerous streak. For a long time, he has been a regular instigator for trouble himself, all too often. He will constantly get his little brother into trouble and enjoy every minute of it. But as time has gone on S4 has learned very well about S8's ways, and has learned how to retaliate. S8 is starting to realize that his little brother is actually getting to be far better at dishing it out than he -- so S8 had better watch out! S4 has been conditioned too well! LOL.