Except this is PR, so it's Dino Thunder and SPD.
DT dropped the ball on Trent after he became good. And SPD barely had anything for Syd to do, and we all know about the infamous Omega Ranger.

So I'm still standing by my point.

But the team wasn't the problem. It was the writing that was the problem.

Hell, Samurai, Megaforce, and Super Megaforce had six members each, and they're not well liked by fans.

Several years ago, we had very large Japanese firm as our client for the project I was working on. Like, one of the largest technology firms in Japan.

Anyway, we had a round of project meetings for a few days, and on the last day everyone was going out for a big business dinner. A couple of the younger Japanese guys asked if I could take them over to Toys R Us (which, at the time, was right near our office - it has since moved). I said sure and took them over.

These guys were both in their late 20s, early 30s. They did not talk much about their families, but when we went to TRU, they were very excited to get their hands on all of the "import" Transformers toys which they could not find back home. They both bought some TFs for their kids and told me how surprised they would be to get toys from America.

Things go both ways; here in the States many geeks are accused of being "Asia-philes" and liking things because they come from Asia; likewise, the same can be leveled at Eastern otaku for being "America-philes."

Even so, they couldn't balance the 5 rangers DT had to the point where Trent stopped having an impact on the story until the White Ranger clone was killed, while for SPD, even after making one of the characters a non-character, Syd still had incredibly little to do. While I still like the teams, it doesn't change that, even with a team of 5 and 6 (Or 7, if you count Shadow Ranger), they had a hard time giving all the members something to do, which is why I'd prefer a team of 6.
And that's only since 6ths are staples that aren't going to be removed, so with only 6 characters, there's a better chance of everyone getting a chance to make a name for themselves.

Again, that's all the writing. The main question was about the team as a whole.

That kinda question has no right or wrong answer. Hell, if you can make it work, have 20 members. Anything works if you're good enough.

Yes, the number of Rangers is not important. Dino Charge will have the most Rangers in a team in history, and so far it's looking rather good.

I may be a bit traditional but I like 6 Rangers. :D

Is it better for a Power Rangers team to have 4 men and a woman or 3 men and 2 women?

Depends on how much you dislike diversity. Lol

Absolutely 3 men and 2 women every time, for me. If possible, even 3 women and 2 men, like Shinkenger did for a short while.

Either is fine for me. Just depends on the story they wanna tell.