It's not uncommon for non-cabover to be referred to as conventional. GP is using the correct terminology.
https://www.innomotivesolutions.com/about/blog/item/cab-over...
https://www.smart-trucking.com/cabovers-make-a-comeback/
https://powertorque.com.au/cabover-vs-conventional-and-euro-...
Non OCE is conventional and OCE isn't, plain as that.
It's not uncommon for non-cabover to be referred to as conventional. GP is using the correct terminology.
https://www.innomotivesolutions.com/about/blog/item/cab-over...
https://www.smart-trucking.com/cabovers-make-a-comeback/
https://powertorque.com.au/cabover-vs-conventional-and-euro-...