The article states:
It can take about a week to remove all the military equipment from the Voyagers, such as radio systems and refueling pods, and “blank” off the parts of the aircraft where that equipment had been connected. Therefore, AirTanker would prefer to keep the aircraft in the military configuration to reduce costs.
But surely the 'other five' will normally be in 'de-militarised' configuration, so the notion that they will be swapping back between civil and military configuration on a regular basis is pure journalistic speculation?
I'm sure that ATrS must have a more robust business plan in place for third party revenue generation than this article imples - and presumably there are also contractual restrictions on military use by (rather then for) non-RAF military services?