As a general rule of thumb making mergers work and repositioning law firms are not particularly speedy processes. But there are always exceptions to rules, and the pace of Berwin Leighton Paisner's (BLP) progress in the first 10 years after the 2001 tie-up between Berwin Leighton and Paisner & Co was very much one of them.

With an entrepreneurial approach that has led to its initiatives being copied years later by rivals and strongly led from the top by long-standing managing partner Neville Eisenberg, for years the firm could seemingly do no wrong. Its expansionist strategy helped it swiftly reposition from unexciting mid-tier to true City challenger. Even though internally one of the key drivers of its growth – a policy of hiring ex-magic circle and other senior names on above average PEP – was divisive at times.

What goes up quickly can come down just as fast though as the firm has shown with two drops in PEP in recent years. And of course, once money is affected, it doesn't take long for dissatisfaction to turn into departures, as BLP has also demonstrated all too often since 2013 – though in fairness to the firm many of those leaving did not do so voluntarily.

But while more than 25 partner exits in 18 months looks more than careless from the outside – even if half of them were pointed in the direction of the door by management – in the grand scheme of things a few bad years can be explained away as a blip.

And by all accounts that is all it looks likely to be in the case of BLP. While average PEP is still far from the firm's peak, both profitability and revenue rebounded significantly in 2013-14, despite a reduction in the number of partners bringing in fees.

But that is not to say BLP does not still require some equally strong leadership from its management team over the coming years as it has to date to fully rediscover the form that helped set it apart from many of its mid-market rivals in the wake of its merger.

On the contrary, with the success of its approach to lateral hiring now demonstrably called into question, the firm needs to show it can both recover its position in the market and build on it without always looking to talent acquisition as the solution.