I have seen many a worthy salesteam sunk by a disruptive senior salesperson.
They do their numbers, yes. But constantly bitch and moan and cause havoc. Always chipping away against pretty much everything other than them inside the organisation.
No chance missed to slate, berate and display downright hate. Towards any and all of management, direction, product, price, quality, delivery, commission plan, basic, rewards, marketing support, pre-sale support, customer service and all other departments as and when they appear in their crosshairs.
I have been in meetings where it's got plain embarrassing.
Even when they come in pairs. Always sitting next to each other. Thick as thieves. Sniping whenever they can.
I have had conversations with the leaders of sales outfits infected with such a virus.
The difficult truth is that you must part ways with these saboteurs.
The sad fact though, is that too few face up to the fact they must cut ties.
Once you've been through this most sapping of energy drains, it's easier to take quick action next time. Thankfully, it is not a completely common occurrence.
And this season's EPL shows a prime example of how it can be dealt with.
Arsenal were in a post-Wenger slump. Regular Champions League football suddenly gone once the twenty-two-year reign of their original French revolutionary manager ended.
The highest paid players, their centre-forward talisman alongside most creative and natural talent, were both considered to "pollute the mood". Repeated indiscipline and spreading discontent towards the younger players ruining the drive towards genuine inclusivity and humility.
No player is bigger than the club. That's an often heard refrain too when disdain boils into public view. But seldom is it acted upon.
Arsenal's young coach, Mikel Arteta, was different.
Despite the apparent 'cost', he was decisive. Got rid of the problem. Banished to (of all places) cash-strapped Barcelona and their boyhood club in Turkey.
Other lesser-lights also not on-board were shown the door as well.
In his own words, when asked the biggest factor for this season's vast improvement, edging closer to UCL return;
Everybody aligned with the same purpose, the same determination and the same level of passion to achieve what we want to do."
It is such a simple lesson. Yet a hugely salutary one.
Does your combined sales effort pass this test?