Many tech YT videos explain the issue of having the pump higher than the rad. The AIO mfr's all recommend the rad hoses to be at the bottom when mounting the radiator in the case. You run the possibility of early pump failure from burning up the pump from cavitation of air in the impeller cavity. Also dramatically reduces your cooling capability as the flow rate plummets.So the rad needs to be hoses up after all then?
The nice thing about the hybrid gpus and AIO 120mm rads are that they fit in the same 120mm fan position as a fan, AS LONG as you rotate the radiator 90°'s so that the end bell hoses are side to side instead of vertical where the rad can only fit in the bottom or top position to clear the hoses.
I have two hybrid gpu rads in my front 360mm fan option location with the rads occupying the middle and top fan mount positions. Both put the rads above the pumps in the gpus. Good cooling and no noise from the pumps since the air is trapped in the radiators.
[Edit] Again lost track of just what hardware you have and was confused by your image until I just remembered that gpu is running a 360mm rad in the AIO. So your current position is what the mfr's recommend. Hoses in the down position. The air bubble rises to the top of the radiator and never gets sucked back in to the pump.