This is a bit of a pet peeve of mine, and you may not care, but I like to separate "Heroes" from "Inspirations."
Inspirations are just that - Artists that inspire you. Bierstadt, Frazetta, Sargent - These guys inspire me. I look at their work, and I learn things about it...but they are not my heroes.
To me, heroes are people still fighting the good fight. I can learn from the legacy of Frazetta, but I can't really figure out how to find work from him. I can't ask him, and honestly, the whole industry has changed since his time. If I tried to do things "The Frazetta Way" now, I'd be doing myself a disservice.
There are some grey areas. Glen Keane is still alive, but at this point, I think he's more inspiration than hero. Your mileage may vary, which leads us to the next point...
Why is this important?
You only have so many hours, so many opportunities to focus your energy, and so much energy to focus. When I break apart my influences in this way, it helps me organize my life better. I think people spend too much time studying their heroes instead of their inspirations. In our desire to work and be successful, it is easy to "hero worship" to the point where you try to metaphorically "wear someone else's skin." You see this REALLY strongly in comic books and concept art. For a while, everyone tried to draw like Mike Mignola or Jim Lee, and tried to paint like Jaime Jones. Man, I LOVE those guy's work, but I think you would be better served trying to paint like your inspirations :) See how your heroes navigate the waters of the industry. You can even ask them questions potentially, which is GREAT.
Look to your inspirations to guide your art. You're going to have to do some more work here, because they are more removed from you...but on a positive note, you and your heroes probably SHARE inspirations....Might give you something to talk about with them....(subtle hint.)
If you are *really* hardcore, do some research and figure out who inspired your inspirations. I learned about the Dusseldorf School of painting from researching who Bierstadt learned from. The deeper you go, the more you're going to have to put into *your* work. If you spend your life copying how someone like Noah Bradley paints, you're going to be a bad Xerox copy of an existing, working artist...but if you go back to Bierstadt, that photocopy gets a little more distorted, and adds a little more *you* to it. If you go back to Andreas Achenbach, you're going to push that a little more.
Heroes can help point your way...Inspirations are the source of the tools you will use to get there.
Hope you enjoyed reading, please share if you feel inclined :) Every new follower is a help!