[Homerson]

There is steering if you are using your arms to make the putter go straight down the line.

NOT if you set up with the cervaical spine horizontal(or close to) to the surface, and rotate the shoulders around the spine, whilst 'keeping' the hands/arms relatively quiet.

Also, if I understand the putting arc correctly, it 'asks' a certain inclined plane of you, and if you don't have a good understanding of which plane you wish to use, or you don't have a qualified putting instructor teaching you, you perhaps are more likely to run into steering issues,due to the myriad of potential planes that you could fall into, rather than the reverse roll proceedure that you're implying with your post.