A few questions, as my knowledge of this case is a bit limited:
1. Did Algy Ward get kicked out of the band in 2007, or did he leave on his own accord?
2. Has Algy Ward come out at any time between 2007 and now indicating he was continuing the project?
3. Any word on how the rest of the band feels/considers this move? Anything from Metal Mind Productions?
Without knowing the answers to those questions, there's a few options we could take on this:
First option, we could create a single additional band page. "Tank", as we know it, stays the same. Another page for Algy Ward's "Tank" (under the name "Tank" as well) is created. An additional line is included in the "Years active" field in both Tanks, indicating that Algy Ward's "Tank" exists. For example: "1980-1989, 1997-present, 2007-present (as Algy Ward's Tank
). A bit in the additional notes would explain why this is the case. This would be the case if Algy Ward restarted the project, from his opinion, or if he essentially created his own new version of "Tank". This would be based on the Queensryche precedent... however... that was also a more clear example of an individual leaving and creating their own version of the band.
Second option, we could simply note in the additional notes of "Breath of the Pit" that the album was produced by Algy Ward alone, and may not be seen by the rest of the band as legit. On the main band page, the additional notes would explain the split with the band. This may be confusing in terms of "ownership," however. It also causes a problem with line-ups. Not a very favorable option.
Third option, is the exact opposite of the first option, where the other band members are given their own band page for "Tank", and Algy Ward inherits the current band page on "Tank". This, to me, is dependent upon whether or not Algy Ward was kicked out or quit the band previously, or if the band simply ditched him. This really isn't that ideal of a solution, simply because it sets a precedent for 'founding members' to be the deciding factor in who "owns" a band, and not who might have the support of a label, or copyright, or whatnot. A very dangerous precedent.
Fourth option, we create two new band pages, in addition to the current one. The current "Tank" page would go until 2007, and then be set to "Changed Name." From that point on, you would have two new band pages created, one for "Tank" with the other members from 2007 onwards, and "Tank" with Algy Ward from 2007 onwards. This maintains the old page as the property of neither one group or another; the information on the page would be reverted back to its 2007 state. It may, however, cause a bit of confusion to our users who see three "Tank"s. Additional notes would hopefully help to resolve that, however.
Personally, I would lean towards the fourth or first options.