This guide is for consultancies plural: firms with employees, associates, subcontracted specialists and a brand on the door.
Three firm-level questions decide the programme: does PI cover everyone who delivers under your brand (employees, associates, subs – in writing); are directors personally protected (D&O isn't optional once you have employees and contracts of size); and would the firm survive its largest engagement going wrong (limits against biggest contract, not average). Get those right and the rest is procurement.