Why another Type 26 yard could matter more than Type 31 capacity

Would another Type 31 or another Type 26 shipyard be more useful?

Another Type 26 yard, provided enough ships are being ordered. Type 31 construction has more scope to increase output within its existing yard.

A second Type 26 yard is preferred if enough ships will be ordered to sustain it. Type 26 represents complex-warship construction, while the Type 31 yard can build experience through successive generations of less complex frigates. The simpler ships take less time to build, giving their existing production line more room to increase output. Type 26 construction has a tighter practical ceiling, so another yard would add capacity where expansion is harder.