You can mark traffic however you like, and create whatever QoS scheme you like within your organisation. You then assign the markings you choose to the queues you want. Most people stick to one of the well-known schemes so that it’s easier for someone else to follow.
Specifically with marking video as AF46, assuming you mean DSCP 46 or EF, then my concern would be that if your also running voice as EF then you may impact the voice quality. Voice works best with low jitter, introducing video packets into the queue may increase jitter since unlike voice, video is not a smooth consistent bandwidth, it varies a lot. The other consideration is that depending on how much of your smaller links video is using you may reduce the overall effectiveness of QoS. If you prioritise too much traffic then you might as well prioritise none - the guide used to be to give the highest priority to no more than about 30% of link bandwidth (with modern bandwidths this is usually not a problem).
