Following hot on the heels of an embarrassing home derby defeat by Sunderland, Newcastle's 6-0 drubbing at the hands of Liverpool – their heaviest home loss for 88 years – has piled pressure on the manager, Alan Pardew.

Certainly injuries have not helped their cause; if Fabricio Coloccini, the focal point of their defence, had been fully fit the backline would not have been exposed to such an extent as in recent weeks. And the tiring Europa League campaign will surely have counted for a few dropped Premier League points this season. However, there's another couple of factors that may explain why Newcastle seem to be in steady decline.

Firstly, the January transfer window is usually a time to make minor adjustments. Newcastle's winter shopping gave the impression of a rebuilding operation rather than a few cosmetic touches to freshen up the squad. In one way it's understandable that the club decided to bring in now what they presumably intend to become four members of the first XI (Moussa Sissoko, Matthieu Debuchy, Yoan Gouffran and Mapou Yanga-Mbiwa) plus the future prospect Massadio Haïdara, as they probably would have faced stiffer competition for the players in the summer (Sissoko and Gouffran were in the last months of their contract). And as much as three of the said players are likely to make a positive impact in the Premier League in the seasons to come – I'm not convinced that Gouffran has the quality ever to become more than an impact substitute – it's questionable whether mid-season was the right time to perform what looked like a serious overhaul of the squad.

Arriving in January obviously denies the new signings from abroad the opportunities to ease into the reality of a new type of football – not to mention a whole new culture – through a measured pre-season. Instead they are thrown in at the deep end during a period in which the hectic schedule offers little time to work on collective schemes, team structure and organisation on the training ground. And while the individual impact of the new arrivals may have been satisfactory so far, the question remains whether adding five new faces in the middle of a season has upset the team dynamics. Possibly even more worrying for Newcastle, the arrival of five new French players in January has, in my eyes, transformed a strategy into an experiment.

Sure, there have been examples of heavy representation of one group of nationalities – or players who share one foreign language – at Premier League clubs in the past. Arsène Wenger has always enjoyed the company of French-speaking players at Arsenal just as Rafael Benítez's Liverpool sides featured many Spanish or Latin American players. While not all those individual players have been a success, the difference in this case is obvious. Unlike Wenger or Benítez, Pardew has no previous experience of working in a foreign league – in this case some experience in France would have come in extremely handy – and neither, as far as I know, does he speak French fluently enough to get across those subtle man-management skills that are required to get the best out of his players – something it's impossible to communicate through interpreters or assistants.

Man-management skills and cultural understanding are some of the most important qualities a manager can possess at top level, which is one of the reasons why what are considered the cream jobs in the Premier League more often than not end up in the hands of multilingual managers who have previously been in charge of players from a variety of cultures and ethnic backgrounds. And as long as the vast majority of top-level footballers continue to be imported, I cannot see this trend reversing.

Looking beyond the obvious downside of the linguistic aspect – which, judging by their untidy defensive organisation, seems to be an issue for Newcastle on the pitch – there are several other factors against having your squad over-represented by players from the same non-English speaking nation. Logically, upon arriving players from the same nation tend to gravitate towards one another and find comfort in each other's company. If there are just two or three you're not likely to hang out exclusively with just them, but when it's such a large group as Newcastle's (10 French players plus a couple with French as mother tongue) they are likely to stick together, which often leads to a slower integration as they find a network already set up, reducing the need to pick up the new language quickly and become independent and culturally adapted.

Small groups of foreign diasporas are not only a part of the modern game (Manchester City have their Argentinian contingent, Chelsea have their Spanish and Brazilian groups) but also positive as it does create a best of both worlds environment; a concentration of countrymen that can provide a small support platform but not big enough to become cliquey and closed as can happen if there are a dozen of you.

This is not exclusively a French problem. A non-English speaking French manager would face a similar scenario if a minibus load of British players suddenly arrived at his Ligue 1 side. Any club with a dozen same-language foreigners on their books runs the risk of a "club within the club" emerging if the manager hasn't got the right skills and experience – and language – to handle them. It can be practically impossible for the coaching staff to penetrate such a clique and if it gets too out of hand they can behave almost like a trade union, acting in their own interests and ignoring the rest of the squad, creating an "us and them" atmosphere.

This could become a real headache for Pardew. As a result of this curious French strategy I would feel slightly worried if I were in his shoes. Having spent serious amounts on – and handed out long-term contracts to – the French contingent the way is paved for a French-speaking manager unless Pardew manages to get the maximum out of his francophone players, which – as a result of this model (or experiment) – has become the key to success at St James' Park. It would be a far less expensive operation to dispose of the manager than to rebuild the squad once again over the summer.