If you have at least 1 copy of Elemental HERO Woodman, you can use Phantom Magician to summon him and search Poly from your deck in your turn, giving you some card advantage. Or you can use multiple copies of Woodman instead. That way, you can keep only 1 copy of Poly in your deck, leaving free space for backrow cards, anti-backrow cards, and Plasma/Dogma support.
Here's the deck I'm using. It's not f2p because I bought the SD a second time, but you can use Decider/Drilldark/Doom Lord instead.
This deck has some versatility because you can either summon your fusions or Dogma/Plasma according to the duel. Trinity can OTK your opponent if you manage to attack; Dogma can override MW and WoD with his huge ATK and Dark City; Dangerous can dump Dreamer.
It looks good. Here's what I will try in order to include big tribute monsters, but still use fusion: use the cats (d-cubed) and more d-hero that can get special summoned easily, dump Vaion and poly and try fusion gate, which is risky, but since plasma and dogma or dasher will be main focus, I don't mind it being there. The heroes can mill stuff easily, so it's not a big issue for speed.
Fusion gate doesn't fit well unless you're going to search it with Pathfinder. It would be great it there was a powerful D Hero to be summoned with Escape from the Dark Dimension. D-Fusion might be used for extra attacks and to fusion and stall during your opponents turn (although the fact that it can only use D Heroes already on the field as materials kinda makes it clunky to use).
Eh, and its reasons like this that people either buy more structure decks, and/or choose to only focus on either the fusion, or the tribute monsters. Think I might just do the latter or go back to Vaion and 1 poly until I can get what you suggested. Seriously though, thanks for all of the help!
I should point out that Dasher doesn't fit well in a pure D Hero deck because he doesn't perform well as a beatstick and he cannot special summon Dogma or Plasma. His best use would be in a BLS deck with Beginning of Heaven and Earth.
Also, Vision hero Vyon isn't the best Poly searcher for this deck. His best use would be to dump down a Hero that you want to be in the grave and banish another Hero from the grave. If you just want to get Poly and nothing else; Blazeman and Wooman are better pick ups.
It depends. 3 D Cubeds are more consistent at bringing Plasma/Dogma out quickly, but you can use a slower version that focuses on using your higher ATK low Lv D Heroes (Drilldark, Celestial, Decider) and protect them with more staples (MW, SRH, WoD). You might also use less D Cubeds if you want to use them only for milling purposes, or only to fulfill Dangerous' fusion requirements.