Sloops gave junior officers independent command

How senior were the officers who usually commanded Flower-class sloops?

They were generally lieutenant commanders or commanders, making sloops valuable early independent-command appointments for future cruiser officers and warfare specialists.

A large fleet of modest vessels created valuable command appointments. Sloops were commonly entrusted to lieutenant commanders or commanders rather than the senior captains required for capital ships and major cruisers. That gave officers early experience making independent operational and diplomatic decisions at sea. It also created a second development stream alongside destroyers, producing cruiser officers as well as specialists in minesweeping and anti-submarine warfare.