Could a larger Indian or Dominion navy have sent ships to Force Z?
Short answerPossibly. It could have contributed ships directly and freed British escorts for the main war zones.
NotesA larger Dominion fleet could have supplied Indian, South African, Australian, or New Zealand ships to Force Z. Local escort forces would also have released Royal Navy ships from commitments elsewhere. That could have made more escorts available in the main war zones and might even have affected carrier availability. The outcome remains speculative, with no fixed task-force composition or guaranteed prevention of losses.