>>44149372Tyrantrum's problem isn't a lack of good move. It has Head Smash to go with its Rock Head ability already. Add in Earthquake for coverage and that's all it really needs.
The problem with Tyrantrum is low speed and skewed defenses. In Pokemon, if you're slow, you better be bulky; if you're frail, you better be fast. It's not as bad for Tyrantrum conpared to the likes of Absol but the SLOW FRAIL MIXED ATTACKER thing is a meme for a reason.