So far, it is doubts that Rangers have acquired during the January transfer window.
The plan was to sign Toumani Diagouraga from Brentford and Michael O'Halloran from St Johnstone, but both deals stalled.
The former has since moved to Leeds United, while Saints manager Tommy Wright intends to select the latter in his Scottish League Cup semi-final team against Hibernian on Saturday.
In the meantime, focus has fallen on comments made previously by Rangers chairman Dave King, about over-investment and the level of finance required to re-establish the club.
The club ought to review their entire recruitment strategy at the end of this window, since at least one of the manager's preferred targets moved elsewhere, but that includes more than the level of finance available.
High wage bill
King and fellow investors will have provided between £15m and £19m by the end of the season.
That includes share purchases as well as loans for working capital and funds to pay back Sports Direct's £5m loan.
Given the ongoing investment that will be required to restore Rangers to a solid, stable, self-sustaining business, King's estimate of £30m from himself and others may well turn out to be fairly accurate.
Rangers currently run the second-highest wage bill in Scotland but are arguably not extracting full value from it as a legacy of contracts offered to players by previous regimes, making the club wary of paying out too much in wages.
Eleven players joined in the summer, with four of those deals involving transfer fees and three of them being loan arrangements with English Premier League clubs.
Frank McParland joined the club as head of recruitment in October and, in the current window, Harry Forrester and Maciej Gostomski have joined on short-term deals, while Josh Windass and Matt Crooks signed pre-contract agreements to join in the summer.
But the failure to sign Diagouraga and O'Halloran will frustrate manager Mark Warburton.
The valuations of the sellers and the prospective buyer were not significantly different but, like many deals, there are further details, including add-ons, that potentially raise the price and payment terms to be factored in.
It weakened Rangers' hand that both signing targets entered the public domain almost as soon as talks began and were clearly the manager's priorities, so handing the selling clubs the edge.
The football industry may be a hive of gossip but it is possible to keep transfer moves private long enough to prevent negotiations being influenced.
It is also common practice for a shortlist of options and alternative targets to be drawn up, since no club has a 100% success rate in its transfer dealings.
Lessons to be learned
King spoke about securing players for the Premiership and investing in the squad, so missing out on transfer targets cause those remarks to be revisited.
Since Diarougaga went elsewhere and O'Halloran remains at St Johnstone, the whole recruitment process has not worked as smoothly and effectively as Rangers would have liked.
Those players signed on permanent deals last year have all contributed to the team establishing itself at the top of the Scottish Championship, in which they finished third last season. Progress is evident.
That work won't necessarily be undone in this window, but lessons need to be learned from it if Rangers are to deliver "at least another five players at an equal or higher standard before we go into the Premier League" as King pledged in September.