Interestingly, they both have different melee weapons: the Peter Cullen Robot has a glowing orange mace, while the Frank Welker one has blades. In the G1 Transformers cartoon they're most known for, Peter Cullen had a glowing orange axe (a bladed weapon), while Frank Welker was the one wielding the mace.
Furthermore, the Cullen-bot had a face mask with no mouth, while Welker-bot had the face fully visible, but with a large helmet- similar to what Optimus Prime and Megatron had in the original cartoon.
In the finale, Alternate!Jamie has a much deeper voice than his normal counterpart - a voice fans will recognize as Spike Spiegel or Roger Smith.
Jax, the unintelligible member of G-Force homage S-Force, is voiced by Alan Young, who also voiced the similarly unintelligible Keyop in Battle of the Planets. Ronnie Schell, who voiced Jason in series as well, voices "Sloane," The Lancer in S-Force.
Scott Innes, who for a while did the voices of Shaggy and Scooby Doo, channels Casey Kasem again to voice Argo, the S-Force leader.