Warwickshire 283 (Hain 58, Harmer 6-92) and 27 for 2 trail Essex 541 for 9 dec (Bopara 192, Foster 121, Browne 84, Patel 4-138) by 231 runs

"We're all mercenaries now," said Brendon McCullum at the launch of South Africa's T20 competition. At least you had to admire his honesty. T20 imports, like politicians, probably need aides alongside them to remind them what town they are in, and which dressing room to go into. If they ever feel insecure or rootless, presumably they just call up their bank balance.

Similar accusations are levelled against the rush of South Africans now plying their trade in county cricket. Signed in a rush while Britain remains in the EU, and while the reciprocal labour deal survives, it does not take much for their emotional commitment to be questioned.

They stalk the counties, making big runs, taking wickets and, by and large, lifting standards. In Premier League football, such signings are viewed as glamorous, part and parcel of the claim to be the best league in the world; in county cricket, the resentment over their short-termism and the loss of a place for an England-qualified player is never far away. The story is a more complex one.

In this fraught climate, occasionally a player can become a much-loved member of county cricket's community. Simon Harmer gives the impression that he can become one of those players. There is something about Harmer that suggests he will not be the sort of Kolpak signing who mentally never unpacks his suitcase. Essex, having initially offered him a one-year deal, have quickly upped it to three. He is seen as a good bowler and a good sort.

Wickets will help, of course, and as Essex, the leaders, pressed for victory against Warwickshire, Harmer delivered them, his Championship tally lifted to 25. On a straw-coloured Chelmsford pitch now turning big but slowly, his offspin is central to Essex's chances of victory. His 6 for 92 in 45.5 overs - the prime reason that Warwickshire followed on 258 behind - made that abundantly clear.

In all, including a brief foray in Warwickshire's second innings - the deficit cut to 231 for the loss of Ian Westwood and Jonathan Trott - Harmer bowled 39 overs in the day. By the end, he must have been so weary that even his floppy fringe failed to spring to attention in his bowling action with its usual vigour. He left the field to a guard of honour.

Harmer bowled at the Hayes Close End from 11.30am until 4.35pm, with only breaks for lunch and tea. His afternoon stint returned 17-10-20-1. Throughout, his predatory semi-circle of close catchers lived in anticipation of reward. Warwickshire's batsmen became increasingly becalmed. It is not often that Rikki Clarke takes 30 balls to get off the mark but he did so here, reaching 7 in 45 balls in all before Harmer's big break-back had him lbw. With a quicker pitch, his rewards might have come quickly. Instead, he needed resolve as well as skill.

He seemed to have been given a well-deserved breather at one stage but it was only for a change of ends. That gambit brought rewards with three wickets in 17 balls to round up the lower order, lbw decisions against Keith Barker and Boyd Rankin and Jeetan Patel succumbing to a return catch.

Patel had laid about him with gusto. Of his 71 from as many balls, - a season's best - 36 came off Harmer in only 28 balls, all but one of them on the leg-side as he struck out with the spin to good effect.

Apart from Patel, the only other Warwickshire innings of note was from Sam Hain, whose 58 was his first half-century in a season studded by a series of single-figure innings. He fell to a cracking wicketkeeper's catch by James Foster, who had received a sighter the previous delivery when Hain's edge bisected him and Alastair Cook at first slip. Ian Bell reached 32 before he jabbed a turning ball to slip.

It might be that Harmer delivered the coup de grace with the last ball of the day. If you want a batsman to block out a final day, there are still few better choices than Trott, a batsman blessed with the method and mindset to slow life down. But he fell to a leave-alone, lbw, to give Harmer his seventh and final wicket of a productive day. No drip-fed resistance from Trott then in the closing hours.

Trott has already summoned defiant hundreds against Surrey and Hampshire this season, both to no avail, but he fell twice in a manner that will not resonate easily with him. It was the combative left-arm pace of Neil Wagner that had defeated him at the start of the third day: a top-edged boundary against the fourth ball of the day when he ducked a bouncer but left his bat in the air; his dismissal against the next when he pulled to square leg.

If Trott is feeling the effects of a challenging Warwickshire season, their chances of survival will be so much lower. They can begin with a defiant draw on the final day, but the odds are firmly with Essex - and an offspinner rapidly planting himself in the county's affections. County cricket still hankers after loyalty and will open its arms to all who give it.

David Hopps is a general editor at ESPNcricinfo @davidkhopps