T-class submarines as pickets for a surviving Force Z

Could T-class submarines act as pickets against the Japanese fleet sent to attack a surviving Force Z?

They could be concentrated for that purpose, with battleships and carriers justifying large torpedo salvos, but the result would depend on positioning and Britain's competing submarine commitments.

A surviving Force Z would give Britain a reason to concentrate submarines along the approach of a Japanese response. A ten-torpedo salvo is defended as worthwhile against a battleship or carrier, despite the vulnerability created by emptying the tubes. Agile cruisers and destroyers are harder targets and offer less justification for that expenditure. British submarine commitments in the Mediterranean, North Sea, and Indian Ocean limit what could be transferred. The absence of such a concentration historically therefore does not settle its value in this altered situation.