Body-shop staffing. Supplying engineers by the head against someone else's plan, with no accountability for outcome, is a different business. There are firms that do it well.
Work priced on a fiction. A fixed price against an unspecified scope is a dispute with a start date. Either the scope gets defined first, or the structure is a dedicated team instead.
Approaches that will not succeed. An inspection problem that is really a lighting problem, a conversion for a design whose requirements are still moving, an accelerator where optimised software on existing hardware would close the budget. Saying so before a purchase order costs a piece of work; saying it afterwards costs a customer.
Claims we cannot support. If a tender requires a certification Faststream does not hold or a metric it cannot demonstrate, the honest answer is that it is not a fit.