Anne's depiction is unfairly biased against her thanks to the Duchess of Marlborough and subsequent male writers of that era disparaging her. Modern academics tend to agree that her reign was far more positive than how she has been characterized. She's actually a fascinating character, and it was her reign that led to Great Britain becoming a state instead of England and Scotland in personal union. That era led to Britain's golden age of becoming a major military power, and she had FAR more power than Victoria ever did, even if she wasn't able to fully exercise it due to illness and the ever-decreasing influence of monarch's power in Britain. She was also very active in her cabinet with her government, architecture, science, writing, and the economy all flourished, and her reign led to Britain's increased stability. Anne was a powerful woman, and her government and rulership was instrumental in creating a step towards the modern United Kingdom when you think about it. Also, she was actually the Queen of England (and Scotland) before the union, so she is even more appropriate as an English leader than Victoria since she had the title. Just had to defend my Queen
Mary was competent, I agree, though she's too controversial probably. I do know that the series has controversial leaders, but something tells me people would not go for Mary I being the representative of England. I do appreciate that call out though.
Matilda would be AWESOME, but I'm afraid she would be ignored or overlooked as merely a pretender (which is ridiculous since she was the rightful heir and her throne was usurped by Stephen). She also never really ruled the country, but almost got it. She did rule many significant lands though, so personally I'd let her in as an alternate leader. You already know my feelings about Mrs. Eleanor, who I approve of, particularly as an English ruler since she actually ruled for Richard.
As for a male leader, I'm biased so James I, I also love the idea of Alfred the Great or Aethelstan. William of Normandy would be interesting as well.