Bit of both
Lorenz Larkin does his best work when he can control the center, his defensive footwork is limited to backing almost straight up and circling wide dodgeball style when he's close to the fence.
Some people don't realize that size matters more than just in the clinch, or power or reach advantage - sometimes being the bigger guy naturally gives you the ability to bully with pressure in a way a smaller guy can't.
Larkin likes to back up and try to counter guys with straight shots - but at his heart he's a kicking centric fighter, and you can't kick productively off your back foot no matter how good you are. He's improved a bit, but he's still at his best when he can be the bully and pressure a guy backwards - not hyper aggressively but he's best when his opponent is outside the blacklines not vice versa. It's not an uncommon style flaw, Thiago Alves has the same issue, and so did Cerrone until the last couple years. It's why Lorenz dropped the split ot TUmenov, becuse he kept conceding the center despite doing his bet work there and was forced to fight off his back foot.
He'd probably beat Costas now - he's more effective off his back foot, but he still would run into some of the same issues.