But Gandhi is the only Indian leader who is well known in the West, and he's a Civ staple. What would the real benefit be of replacing a well-known figurehead who was an iconic representative of their nation with a virtually unknown figure simply because they actually governed? FDR didn't do much actual ruling, either (ill, incapacitated, US Presidents don't have that much power anyway, most power is with the Supreme Court or the Congress/Senate).
You could replace Wilhelmina with William of Orange (also somewhat of a Civ staple, and he had a cool beard), and Victoria/Elizabeth with Churchill (All the other British leaders with actual power are too recent [i.e. Boris], too obscure [i.e. Wilson], too controversial [i.e Thatcher], too infamous [i.e. Chamberlain], too foreign [i.e. William the Bastard], or too mythological [i.e. Arthur]).
So you would have essentially replaced two female leaders with male leaders, at a time when it seems Civ wants more female leaders, which would inevitably lead to relatively obscure female leaders being chosen (like the Portuguese Queen in Civ V)
So I don't really want to replace beloved, iconic female monarchs with lesser known males who had actual power if it means that other civs have a more iconic/important male leader replaced with a lesser known female leader for gender equality.
TLDR: please keep Elizabeth/Victoria as the British leader
Attlee, Eden, and Macmillan are not nearly famous enough.