I posted an article recently about the importance of people in M&A (I don't mean the suits doing the deal, I mean the employees who work for the organisations involved!). 

Whilst it is often the case that DD on management teams will be carried out during a process it is less likely that any similar exercise will happen for the lifeblood of the business - its workforce. 

I am not suggesting that this sort of approach will work on all deals - the costs are likely to be prohibitive in the lower mid market - but it is certainly something worth putting on the critical path. Any action to improve team working either immediately pre or post transaction is likely to have huge benefits as the two businesses continue their journey into the future.