[lkdsajflkfdsjg]

> Contrary to managements' viewpoint programmers are not fungible,

In any reasonably written project they actually are. If your experience is that they are not then you have worked with badly written and badly documented projects.

> and you can't just drop them into each others projects on a whim.

Indeed you don't want to mix and match too much. Programmers need a ramp up time and teams need time to have cohesion.

Essentially programmers are replaceable but there is a non zero cost to replacing them.