IMHO a complete waste of two good engines and a soon-to-be expensive mistake.
It looks like they are trying to convert a dumb barge into a self propelled barge.
The verados like most petrol outboards are by nature low torque high revs engines. for a heavy steel rig such as this, you need to be able to turn a big prop at lower rpms for any kind of efficiency. Hence all such vessels come with diesel inboards turning at 1200-1800 rpms.
Fuel consumption would be off the charts compared to a diesel inboard.
I don't believe the engines will last very long here. Watch out for "For Sale - 2 X 300 HP Mercuray Verados, low hours, barely used, blown powerhead"