Yoda loses to Sidious due to circumstances. Both Mace and Yoda are more powerful than Sidious. Anomaly, your speculation is merely that, and contradictory of Lucas.
Prove that Mace and Yoda are more powerful then Sidious. Yoda and Sidious didn’t really finish their fight, so we don’t really know anything, except Yoda ran away. And although Mace beat Palpatine in a saber duel, he is NOT as powerful force wise as Sidious. Sidious is at least equal to Yoda, and Yoda is more powerful then Windu (as Windu admits this himself) If Yoda was more powerful then Windu and Windu was in fact more powerful then Sidious, then Yoda would have raped Sidious regardless of circumstances. This did not happen, at all.
I'll admit, Mace is better then Sidious in saber combat because of Vaapad. And more then likely Yoda is slightly better then Sidious in terms of saber skill. But Yoda and Sidious are at least relatively equal in terms of Force prowess, with maybe Yoda having a slight edge, but not much. Mace is not in that league of force power.
And how am I contradicting Lucas exactly?