For students of the Scottish rugby scene, there is something disturbingly familiar about the revolving door policy being applied to Glasgow Warriors' battle for No.10 as they aim to salvage something from their Heineken Cup campaign.

The club have played 12 competitive matches this season and, for the eighth time, the playmaker has been changed for tonight's meeting with Castres.

The pattern was set at the start of the season when all three contenders were fit, and Duncan Weir began the first game, to be replaced by Ruaridh Jackson. Weir reclaimed the No.10 shirt for the third game, before being replaced by Scott Wight after he was injured.

Jackson's recall the week after that made it five changes in the opening five matches and he had a five-match run. That ended when he was replaced by Wight, who he then replaced once more before fit-again Weir was reinstalled last week. Wight's selection for tonight's match makes it another five changes in five matches, then.

Given the different playing styles of the trio, it is a dizzying sequence and what makes it all the more curious, as Glasgow struggle to find form, is that it is decidedly reminiscent of head coach Gregor Townsend's own career with the national team.

For several years after he finished playing, Townsend remained Scotland's most-capped back with 82 appearances, but he was not the most capped stand-off, an honour held by a fellow Borderer, and a direct contemporary. Craig Chalmers started 55 of his 60 Tests at stand-off as opposed to Townsend's 49, and it is a remarkable fact that the Warriors head coach never started more than six successive Test matches in his preferred position.

Of Scotland's all-time top 10 most-capped stand-offs he also has the poorest success rate (35.71%), well behind that of Chalmers (50.9%) – the only one to boast an overall winning record – and Duncan Hodge (43.33%), the third of those who regularly vied for the position in that era.

What scars, if any, that has left only Townsend knows, and the nature of these things is that even he may not. However, as Chalmers' former Melrose protege Wight gets his latest chance ahead of the two internationalists, it is an important match for him and for Glasgow as they try to establish the sort of consistency that was their hallmark last season.

For all the claims the management and players are understandably making about believing they can still qualify for the knockout stages in Europe, rediscovering what they do best, or at least establishing some patterns of play upon which they can rely, would seem the priority over this weekend and next's double-header with Castres.

That is reflected in the selection, since it is hard to imagine that Sean Lamont, the leading Test try scorer in the current national squad, would have been rested tonight if there was real belief that they can pick up the bonus-point wins required to get back into contention in their Heineken Cup pool.

Wight, despite being the least vaunted of the trio, and comfortably the oldest – at 27, has a great opportunity to demonstrate he is most capable of providing the authority required of a playmaker who knows what he is capable of and how to best utilise for the team.

With Graeme Morrison poised to return from injury it is also a key match for the midfield combination of Peter Horne and Stuart Hogg, while Warriors supporters will hope for their first sight of Sean Maitland, the former Canterbury Crusaders full-back/wing.

Partly enforced by injury there is consistency of selection in the front five of Glasgow's pack, but the back-row – another key decision-making area – has again been reshuffled.

There are, of course, exceptional examples of teams such as Manchester United, where Alex Ferguson rarely picks the same side for successive matches because the quality of the individuals and understanding of team ethos is such that interchanging players makes little difference.

However, that takes time to generate and a far more tried-and-trusted method of achieving success early on is to establish your best team and make changes only when necessary, rather than pandering to egos by sharing out first-team appearances under the guise of encouraging competition for places.

In that context Townsend, during his time as Scotland's attack coach, seemed to manage to retain popularity with players in spite of his record, but being head coach means having to make tough decisions, not least in selection. These two meetings with Castres may, then, be less important in their own right than they are in establishing just what his strongest team is for the two matches thereafter, which increasingly look as if they will define Glasgow's season as they seek to justify the vast increase in their playing budget.

Holding on to the 1872 Challenge Cup, which will again be played over Christmas and new year, may not be that big a deal in itself in the greater scheme of things, but the number of points they accrue from those two matches against Edinburgh will give a strong indication of their capacity to sustain a challenge in the PRO12 thereafter.