Naples, April 18, 11pm local time – The dust is settling on a textbook European away performance. Arsenal have kept Napoli, one of the most potent attacking sides on the Continent, at bay, beating them 1-0 at the Stadio San Paolo to secure safe passage to the Europa League semi-finals.

They sit third in the Premier League, on course for a return to Europe's big table, the Champions League, and are within touching distance of a first European trophy in 25 years. Were he to allow himself a moment's pause and reflection, Unai Emery could be very satisfied with his first season as Arsenal manager, just a month from its conclusion.

North London, May 5, 6.30pm – A draw with Brighton & Hove Albion at the Emirates is no more than Arsenal deserve for a drab, disjointed performance. They have now gone four league games without a win since returning triumphant from Italy. They are fifth in the table. They need a minor miracle to finish higher.

In an increasingly binary world, there is diminishing patience for nuance, grey areas are being eroded and everyone and everything must be stuffed immediately into one ill-fitting category or another – success or failure, genius or fraud, Leave or Remain; dither, and prepare to be bulldozed along with the fence you sit on.

So, then, when it comes to assessing the job Emery has done at Arsenal this season, strong and vastly opposing opinions will be expressed. But, in truth, it's difficult to be conclusive; the Gunners' wild swings from thick to thin, black to white, have left only a grey campaign upon which to reflect.

With one game still to play, they are already four points better off than last season, and likely to finish one position higher than the sixth of Arséne Wenger's 21st and final full season in charge of the club – progress.

There was a 22-game unbeaten run between August and December. Emery has managed to fit both Pierre Emerick-Aubameyang and Alexandre Lacazette into his team, solving a difficult stylistic quandary to yield 44 goals from the pair. And, leading Valencia 3-1 from the first leg of their Europe League semi, Arsenal have one foot in a European final.

New signing Bernd Leno, eventually, has supplanted the retiring Petr Čech in goal; the semi-regular use of 3-4-1-2 has improved Sead Kolašinac's form, better suited to a wing-back role that full-back; a spell on the sidelines appears to have reinvigorated Mesut Özil, and Granit Xhaka has come closer than ever to fulfilling his potential in central midfield.

So far, so impressive.

But there is also the concerning matter of their inconsistency, and propensity for exiting spells of strong results and fine performances by crashing immediately into sustained runs of dire form, as has been the case in recent weeks.

Often reactionary, there is no obvious, long-term tactical vision in the way Emery has set out his side, and Arsenal have been a defensive horrorshow for much of  the season, shipping 50 league goals for the second season in a row; Manchester United (52) and Watford (55) are the only top-half sides with leakier backlines this term.

Even if they win away to Burnley in their final league fixture of the season, the 70 points they will finish on will be Arsenal's third-lowest in the last decade.

Replacing Wenger was always going to be a monumental task for whichever manager was presented with it. Emery finds himself in the difficult position of having to fill the void left by a totemic club legend, while also unpicking the damage done by a fading icon who'd been allowed to cling to power too long.

So broad was Wenger's influence at the club that Emery is not expected replace the Frenchman single-handedly. Wenger was, in many ways, the last of the old-school managers, figureheads who were at once head coach, sporting director and spokesperson.

Emery's remit is narrower, allowing him to focus on rebuilding Arsenal on the pitch, consulting on recruitment and shaping his squad; the financial health and structural direction of the club is not his concern.

But his job at hand is still a long-term one. Without the finances of a Manchester City or Paris Saint-Germain, there is no quick fix for Arsenal, no shortcut back into the top four and title contention – the £70million they spent last summer is modest by modern standards, and the £40million budget Emery has reportedly been given this year is a comparative pauper's sum.

There have been plenty of bumps in the road, and there are questions yet unanswered, but Emery has shown enough this season to suggest he should be afforded a little more patience, football's – and society's – rarest commodity.