Is there an adjective for people who work poorly together?

I'm looking for an adjective that describes a group of people who don't get along, who work poorly together, who don't necessarily like each other. A word that means or implies interpersonal difficulties, but not ones that are impossible to overcome.

Example:

Several ____ coworkers caused the project to be delivered late.

Some words I've come across that I don't think fit:

• Inharmonious: This is probably the closest, it just sounds very clunky. I wouldn't use it in everyday conversation. If I can't find anything else, this is probably what I will use.

• Incompatible: This has a more absolute connotation that I want. If two things are incompatible, there is just no way around it.

• Antagonistic: Close, but it doesn't convey the "interpersonal" part. If I said "several antagonistic coworkers," I'd be more inclined to think they were antagonizing someone outside of the specified group of coworkers.

fractious

1(typically of children) irritable and quarrelsome: ‘they fight and squabble like fractious children’

1.1 (of a group or organization) difficult to control; unruly: ‘King Malcolm struggled to unite his fractious kingdom’

‘After going backwards at the election and losing ground in opinion polls since, Opposition MPs are cranky, fractious and looking for answers.’

Oxford Living Dictionaries, Fractious. https://en.oxforddictionaries.com/definition/fractious

Fractious can describe individual people, but more often describes a group or an organization.

I personally find the term over-used, but consider dysfunction or dysfunctional:

abnormal or unhealthy interpersonal behavior or interaction within a group

(link and definition from M-W).

It doesn't fit your example sentence, but a slight tweak gives:

Rampant dysfunction among the coworkers caused the project to be delivered late.

A common term for people who do work well with others is team-player. So you could say:

Several co-workers who are not team-players caused the project to be delivered late.

If you want a term that is less perjorative, then uncooperative is, perhaps, the most straightforward word to use:

Several uncooperative co-workers caused the project to be delivered late.

Another possibility is individualistic:

Several individualistic co-workers caused the project to be delivered late.

If you want a term that describes the group as a whole, then incohesiveness is possible:

Due to incohesiveness, the team delivered the project late.

Alternatively, you could put it the other way round, and use cohesion:

Due to lack of cohesion, the team delivered the project late

Finally, you could use uncollaborative, although this does not appear to be a dictionary word. The meaning, however, seems to be reasonably clear. See: Is “uncollaborative” a word?.

Several uncollaborative co-workers caused the project to be delivered late.

How about quarrelsome, intransigent, uncompromising, inflexible, or unyielding?

M-W:

quarrelsome: apt or disposed to quarrel in an often petty manner

intransigent: characterized by refusal to compromise or to abandon an extreme position or attitude : uncompromising

uncompromising: not making or accepting a compromise : making no concessions : inflexible, unyielding

inflexible: rigidly firm in will or purpose : unyielding

unyielding: characterized by firmness or obduracy; characterized by lack of softness or flexibility

Each of these common all too common traits results in interpersonal difficulties, but not ones that are (necessarily) impossible to overcome. They often end in the kind of failure you describe:

Several quarrelsome OR intransigent OR uncompromising OR inflexible OR unyielding coworkers caused the project to be delivered late.