Threatened project deadlines often trigger a last minute recruitment phase.  This generally happens in large projects where there are several layers of management.  

Over recruitment is done in answer to the question posed at management meetings "...so what are we doing about this crisis?" to which the answer is often "...well, we've just taken on a whole bunch of people to make it right!"

Extra manpower brought in like this can help but certainly not in proportion to the cost.  Extra manpower has to be trained, fed, supplied with coffee, transported motivated.  And on that 'motivation' aspect, with a mass of 'under-utilised' manpower, there is always that ever-present potential for idle gossip; and disillusionment, that can be infectious, and that can spread like wildfire.

And you can bet, that your 'new people' will imbed themselves very cleverly into the work structure. So that the decision to hire will have seemed much easier that the decision you will have to make eventually (and after a lot of salary payments) to reduce the numbers.

There is only so much room around a console, and only two hands at a time can hover effectively above a keyboard.  Only so many pairs of eyes that can review a document.

So if that crisis really does demand an increase in workforce, better let the men on the ground contribute almost wholly to the decision on how many, in what disciplines, and in what capacity to recruit.  Involving the workforce in that kind of decision will very likely bring some good independent ideas to deal with the cricis as well.