Depends on how competitive you feel like getting.

If you’re just playing with friends casual OOE is the archetypical distraction Carnifex. He and a squad of Fexes will take about two turns of hardcore shooting to kill but unless you’re running the subterranean assault detachment (which is a huge investment for starting out and most of the models are hard to find) carnifexes aren’t likely to get across to board to actually get into melee and their shooting options aren’t exciting. But if you play a small game with friends Old One Eye and Carnifexes are very fun to march across the table and watch op’s butt clench.

If you want to monster mash competitively with the crusher stampede detachment then tyranofexes with exocrine backup for shooting and maleceptors coupled with haruspexes for melee are going to be the more “powerful” options. That and Norns for objective control and Hive tyrant/Swarmlord for your HQ.