This mimics my mobile product team's battle with the marketing team that is supposed to own the companies 'tone-of-voice' in all material (digital, printed etc)

This mimics my mobile product team's battle with the marketing team that is supposed to own the companies 'tone-of-voice' in all material (digital, printed etc). Have multiple stories on waiting for resources, such as images and text that took weeks to get and then were not used as they didn't follow the guidlines given ('text can be max x char long', 'image resolutions need to be w times v'). We have all but given up on trying to involve them, as it will slow everything down to a crawl if we do.