I think that by EoS, Bakugo and Todoroki will still be close in strength to Izuku, albeit at that point Izuku will be stronger than them. the thing about the 6 quirks is that
1) most of them are relatively weak in of themselves
2) given that OFA has reached quirk singularity as stated by the original user, Izuku might not be able to ever become strong enough to handle the full load of OFA on his own. Hence he might need the 6 quirks solely to boost his body to the point to where he can handle OFA 100%. For example, if he mastered black whip and essentially cloaked his body in black whip like Venom, he could increase his physical abilities to allow him to use higher percentages of OFA without his body actually needing to become stronger.
Furthermore. It has been shown that it was the fault of the hero society to rely on All might alone to be the defender of peace. As we can see, now that all might isn't there, the heroes are in very big trouble. Hence the new generation shouldn't repeat the mistakes of the old. While Deku will be the #1, Bakugo and todoroki will still be able to defend the peace if Deku dies or is unable to serve.
lastly, while Deku got a version of OFA that is way stronger than what All might got, it is similarly true that Todoroki and Bakugo got quirks that are far stronger than their old gen parallel, Endeavor. Once his quirk is mastered, Todoroki would essentially have no weaknesses. Due to this, his damage output will be far greater than endeavor's(which was already insane as fuck) once he is in his prime. It is entirely reasonable for Torodoki to surpass not only endeavor but all might as well, after all, he was created for that exact purpose.
as for bakugo. Given that his quirk is explosions rather than just fire, I think its safe to say that he has a far better damage output than endeavor does at base. Now obviously Endeavor is far above him as of now due to countless years of training, but give bakugo enough time and I could easily see him surpassing endeavor and even all might.
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one last thing. The ability to use the quirks of the previous users was actually a quirk evolution of OFA. Izuku already has an evolved quirk, he just needs to master it.
But as for Todoroki and bakugo, they've yet to undergo quirk evolution. Given that Toga, Shigaraki, and Geten were all able to accomplish this, I think its very likely that Todoroki and Bakugo will as well.
Given how big of a boost evolution gave OFA and the villains, Im sure that evolution would make Todoroki and Bakugo easily some of the strongest heroes in history