With Hawkman, Time is Relative

Been thinking about the time theory that Robert Venditti brought up in Hawkman No. 5; the theory of how time is like an ocean, with all the past, present and futures floating on top. For regular people like us, and even most comic book characters, space is accessible. We can stay in one place, or we can go up, down, forward, backward, and side to side. But the one thing that we can't escape from is time. We can't go back or forward, we are prisoners in our own time. Our past selves are there, and our future selves are there. But we cannot access it. We're prisoners of the now, Edna Mode-style.

However, it is said that time is not the same all across the universe. There are many phenomena, like black holes or wormholes that alter time. For example, we saw this illustrated in the movie Interstellar. They landed on a planet near a black hole. Because of gravitational time dilation, one hour on the planet was seven years of Earth time. So depending on where you are in space, time moves differently.
In the letter column of The Shadow War of Hawkman No. 2, writer Tony Isabella explained why Hawkgirl was still being called Hawk"girl", even though she was a married woman. his theory was that a lifespan on Thanagar was three times longer than on Earth.  So a 30-year old woman would still be in her "teens". Thanagar is in the Polaris Galaxy so the gravitational pull on Thanagar would be different from Earth's. So that would mean time runs differently on Thanagar than on Earth as well. It has also been mentioned that gravity on Thanagar is stronger than on Earth, making Thanagarians much stronger than humans. And that would make time slower as well.
So Hawkman has lived all these different lives across space and time. Because of the distortion of time, it is entirely possible that some lives overlapped. It is also possible that some lives started and ended while others were going on. This is the thing that sets Hawkman and Hawkgirl apart from the other heroes on Earth. They are two individuals who are not prisoners of time. Not only do they go across space, but they also go across time. Because of their reincarnation cycle, and because of the effect the Nth metal has on their life cycles, it is entirely possible that there are two or even three Hawkmen or Hawkgirls at the same time.
In Scott Snyder's Justice League, Kendra will be meeting Shayera Hol in a future issue. At the same time, it is very possible that Shiera is also out there somewhere. With Hawkman, he is going through time in Venditti's current story. He is not a prisoner of time or space. He is traveling freely through space and time and gathering the info and tools he needs to confront the coming threat. So when we think of Hawkman or Hawkgirl, we need to think outside the realm of time. With these two heroes, anything is possible, and much more fun.
This is all just me thinking out loud but it's a very interesting discussion. I'm no scientist so I'm sure my theory is way off somewhere. Feel free to shoot holes in it and make it better.