Royal Bank of Scotland might just have taken a big potential problem off the hands of First Minister Alex Salmond, and of any future independent Scottish government. 

RBS's plan to move its head office nameplate from Edinburgh to London in the event of a Yes vote should ensure that the Bank of England will remain its lender of last resort, and that a Westminster government would have to stump up the capital if another financial crisis prompted a need for a new bail-out. It might be tempting to get wrapped up in the symbolism of RBS moving its plaque south. The No camp will likely make much of this, and of similar moves by other banks, between now and next Thursday's vote.

But what is more important from a practical perspective is that the moves by RBS and other banks to set up English-registered holding companies remove a potentially very significant risk from an independent Scotland.

It certainly appears to knock on the head the oft-heard argument that Scotland could be bankrupted by bail-out costs if a future global financial crisis brought the banking sector to its knees again, and make warnings about what happened to the likes of Iceland and the Republic of Ireland last time round largely irrelevant.

And it would have been surprising if RBS had not decided to move the domicile of its holding company in the event of independence, given previous comments from chairman Sir Philip Hampton about it being unusual for small countries to be home to the headquarters of big banks.

A raft of banks followed RBS's lead yesterday by unveiling plans to move their plaques south, including Glasgow-based Clydesdale Bank and Tesco Bank, which has its headquarters in Edinburgh. Bank of Scotland owner Lloyds and TSB said they would establish new legal entities in England in the event of a Yes vote.

It is good for customers and staff that these banks, unlike Prime Minister David Cameron, have some plans. We were reminded this week that Mr Cameron is not making contingency plans for a Yes vote. Such failure to plan for a possible outcome would be unlikely to stand Mr Cameron in good stead if he were head of a bank or other major company.

The stream of announcements from the banks, which followed comments from Standard Life on Wednesday about planning for new regulated companies in England to which it could transfer parts of its business if needed, is unlikely to have been music to the ears of the Yes camp.

But how negative is the news for the pro-independence camp, in reality?

It remains to be seen what it will do to people's voting intentions.

But RBS, Tesco Bank and Clydesdale appeared at pains to emphasise the shifting of their nameplates would have no significant impact on employees or customers. TSB also played down the actual impact of its move, and Lloyds did not flag any big shift of personnel.

Epitomising the tone of the banks, RBS chief executive Ross McEwan told staff in a memo: "This is a technical procedure regarding the location of our registered head office. It is not an intention to move operations or jobs. Our current business in Scotland, including the personal and business bank, IT and operations, human resources and many other functions, are here because of the skills and knowledge of our people, and the sound business environment.

"So far, I see no reason why this would change should we implement our contingency plans."

Given there is unlikely to be any great change in the split of where the banks' profits are made, there should not be any major corporation tax implications from their contingency plans. So it is difficult to see much downside in these plans for the Yes camp, with no suggestion at this stage of a southward drift of actual operations even in the longer term.

Life and pensions group Aegon UK has for years been run from Edinburgh, but registered in London.

In reality, much of RBS's decision-making is already in London, while Clydesdale has an Australian owner.

The Yes camp, although also having to cope yesterday with Weir Group chief executive Keith Cochrane's forthright reiteration of his No stance, could take comfort from interventions from venerable Edinburgh merchant banker Sir Angus Grossart and Aberdeen Asset Management chief executive Martin Gilbert.

Sir Angus, who has spent his career assessing and managing risk and showed impressive vision to dodge the mayhem of the global financial crisis, told a newspaper that some commentary on the referendum's impact on financial markets had been "severely overstated".

He said: "It is getting out of hand …To hear some of the comments you almost expect people to be predicting a plague of locusts or mice next."

And Mr Gilbert declared: "I think an independent Scotland would be a big success."

The views of these two senior figures should carry some weight.

And on the all-important practical level, which the No camp has been keen to dwell upon throughout the debate, it could be argued the moves by the banks are actually net positive, given any future independent Scottish government will not have to make contingency plans for huge banking bail-outs.