By “weight the risk” I think you mean taking the expected value of the payment e.g. there is a 10% chance that these guys just won’t pay, let’s only count 90% of the final year payments, rather than adjusting the payment expected in a net present value calculation for the time value of money.

The former would be pretty amatuer, the latter unforgivable.

My observation of the public sector is that seems to have an inbuilt refusal to assume that the other side will play dirty.