The aggressive regular to your left will always have a big advantage over you in each hand, as he will act last. In other words, he will first see your action before accepting his own.
You will make all your decisions blindly, without the slightest understanding of how your opponent will react. And this is too big a handicap for your opponent to overcome.
Moreover, you will not play against fish, but against another reg, who will probably be not very far from you in terms of skill level, and therefore, your edge will be minimal.
Once you start playing with regs, you will forget about the main reason why you are sitting at this table, because of the fish! And this is a disaster.
Thus, with all of the above, it is very important to be able to maintain calm and sanity and avoid the so-called "reg wars". Even if you win one battle, you will still lose the entire war.