From a financial perspective, they are a huge risk. They will suck up huge amounts of funding, both in outlay and running costs.
In terms of big ticket procurements the CVs are not huge and not high risk. if you want to talk about huge and high risk let's look at MRA4 (wrong procurement choice), Typhoon (wrong era, old design, wrong role), FRES (will the army ever make up its mind, v expensive already), FSTA (will it ever work). The CVs are bang up to date, relevant for today, have a life way beyond any of the above (50yrs planned life) and ar efull of low risk technology.