Guess the Name

The Name Game
Sara's second son (and Pierre's)

my only clues:
Begins with G or H, is art-related, and difficult
is not one of the ninja turtles
Augustus is his older brother

And NOT:
Sam, Arnold, Alan, Bryson, Burke, Gerald, Harvey, ("getting closer," she said)
Durant, Irving, Lamar, Jack, Harry, Pedro, Kurt, Emerson, Hermenio, Daniel, Devan, Lucien, Sheridan, Kaiser, Pomeroy, Riordan, Marshall, Reuben, Sydney, James, Fontleroy, Phillip, Taggert, Roscoe, Hubert, Marcus, Sandy, Justin, Phelps, Payton, Rylan, Sidney, Melbourne, Thurston, Marcellus, Loren, Garvey, Jehoshophat, Valerian, Rembrandt, Picasso, Claude, Vincent, Jan, Johan, Salvador, Jackson, Renoir, Leonardo, Monet, Engelbert, Kinsey, William, Oakley, Ridley, Russell, Kandinsky,  Craig, Xander, Quant, Byron, Hieronymous, Gombert, Hamlton, Harrison, Grint, Geronimo, Hobart, Ferris, Grant, Hetty, Gabriel, Gaston, Gavin, Geoffrey, Giotto, Godwin, Gottfried, Gustave, Hadley, Hamlin, Havelock, Hawthorne, Henri, Gustav, Georges, Giuseppe, Gilbert, Godfrey, Gardner, Gerard, Hadrian, Handel, Alexander, Adrian, Harbin, Giles, Gilead, Romulus, Marcus, Ferdinand, Jomo, Habib, Hakeem, Grayson, Harding, Ghent, Gladison, Grimley, Horvath, Gormison, Homer, Remus, Hamburg, Gunnar, Hessian, Paul, Pollack, Polter, Ormazd, Herbert, Goliath, Aurrellius, Tiberius, Constantine, Honorius, Pulcheria, Zeno, Tacitus, Pliny, Octaavian, Galbraith, Henley, Horace, Horatio, Heath, Heathcliff

I kind of give up
I have a book of 35,000 baby names
I have months to figure it out

G
H

any ideas?

Hamilton, Halsey

Haley, Hanson, Harper, Harley, Harlequin, Grimaldi, Gilbert, Gordon, Gellar, Hargrove, Hugh, Hewlett, Aragorn, Gandolf, Gimli, Gino, Harker, Hannibal, Hector, Gormenghast, Graham, Galton, Habanero, Hilton, Harvard, Harv, Gabbard, Gibbon, Hershey, Grinnell, Humphrey, Hagrid, Heston, Galt, Grigoire, Gulliver, Hinkley, Hubert, Holland, Higgs, Higgenbottom, Hummel, Himmel, Hamlet, Hammett, Hammond, Gaia, Gaiman, Gaius, Hefner, Helmand, Helvetia, Hansel, Hanley, Goddard, Godot, Godwin.