Why a cheaper Type 47 could displace the Type 83

Could Britain build a cheaper Type 47 alongside the Type 83?

Not safely under current yard constraints; the cheaper ship could occupy the same production capacity and become a political substitute for Type 83.

The historical Type 82 and Type 42 comparison illustrates how governments can select the cheaper design to claim fleet numbers. A lower-cost Type 47 may be a sensible ship in isolation, but it would compete for the same constrained construction capacity as Type 83. The yard building Type 26 follow-ons cannot produce both programs simultaneously without expansion. Under those conditions the cheaper class is likely to replace the high-end destroyer politically and industrially rather than supplement it.