My take is having only two AP's for even a SHTP is marginal. The reason being if one goes down, which it most likely will, then when you mount the spare, then you have no spare.
For RTW, having just two self steering units, both electrical, is putting all your eggs in one basket, so to speak. The General and I both agree on that. For peanuts, PIXEL FLYER could have a golf bag of backup tiller pilots that would work most of the time if both main AP's go down. I agree with Alex's analysis: his voyage is in jeopardy and he is not yet close to entering the Southern Ocean.