No, for 2 reasons:
1. It's not a Fusion Summon, but a regular Special Summon
2. Even if it was a Fusion Summon, the Fusion Material isn't in the Graveyard.
You can still use De-Fusion on it, but it just sends it back to the Extra Deck and nothing more.
It should as, even though Polymerization is not involved, these Tag/Contact Fusions used by the Gladiators/ABCVWXYZ/Neos are still considered Fusion Summons.
He's right. Only fusions using polymerization or a poly substitute that counts as poly are treated as "proper fusion summons" fusion monsters that are not properly fusion summoned can't be summoned from the graveyard. Glad Beasts dont fusion summon. They special summon from the extra deck.
Not really, Semi-nomi monsters (Must first be Special Summoned..) still can be summoned from the GY since its summoning condition was reached prior it to be sent from the field to GY. Only nomi monsters (..and cannot be Special Summoned by other ways) cannot be special summoned from the GY even if it was properly summoned previously.
TL;DR: De-Fusion works on Gladiator Beast Heraklinos, it will be returned to the Extra Deck and no materials will be special summoned for a reason: 1- That's not a Fusion Summon, so there aren't any fusion materials to be special summoned.