Can confirm that 'robuse' was an earlier term to name / describe what is now generally referred as ikkko, ikkajo, first control, etc.
For a very short time in California I had the pleasure and good luck to take just a few classes with a great sensei who had trained directly with O;sensei. In a casual remark in class, 'robuse' was mentioned as alternate name.
I believe (let's not get into a Japanese language war here) it comes from 'ro' which is Japanese term for oar but is different from western use - better term would be scullying. Period Japanese rowing manuals show similar grasping that would be used for the first arm control technique. Add to the mix the rowing techniques of Funakogi undō derived from Shinto exercises and it makes sense.
Was it a Daito ryu name? I don't know. Did O'sensei come up with it to better describe the technique? I don't know. I have also been told the rowing exercises are NOT from the Daito ryu teaching curriculum.
I actually learned that "arm rowing" was the "literal" translation because of the way you would row the boat (as you described). I'm not sure where O Sensei picked up/out the names but know that our Yoseikan Budo names (when translated) are very desriptive of the movement/throw you're doing. Interesting that all three of the great Masters that MM worked with were descriptive in their terminology rather than names that sounded "pretty" or flowery.