Jerome from halo wars would be a better a remplacement, not a random spartan IV who thinks is over spartans IIIs not the community fault, 343 have been trying to do spartans IV look greater than a spartan II since Halo 4, and that's his fault.Being obsessed over spartan generation is entirely the community's fault. You are assigning ill will to both the characters and 343 because they dared not be a spartan II.
Also jerome is not the only spartan II on service.
343 has done nothing to say SIV's are better. Locke did not say he was better than chief. He got an assignment and he performed it to the best of his ability. 343 isn't the one starting a million threads about "Which spartan generation is best" or "who beats who in 1v1 fight" that's entirely the community. 343 has generally gone with an approach that they are all spartans, but anything resembling equality is not tolerated by the community.
Spirit of Fire should be lost in space for over a century, and only got brought back into the setting due to more plot shenanigans than anything the S-IV's have pulled. I don't really see what makes Jerome so special beyond being effectively the same character.
It's not for being obsessed but it's a fact that project orion were test subjects, spartans III cannon fodder and the spartans IV odst's with a better armor and again is not community's fault, since the beginning showed us the spartan II as a definitive soldier, they passed a lot of training and brain wash to be the definitive soldier, and it's to mention the augmentation but the mjolnir amor increases the individual's capacity as well, it's like multiply something that has been multiplied already.
You got a point, 343 has not said that spartans IV are better, but in Halo 4 another random spartan says that she thought he was taller, another random guy that is not even an spartan saying that the chief was old and crazy, that the spartans IV can do the same or better job than a spartans II, in halo 5 we played 13 of 15 missions with another random spartans IV who killed the leader of the covenant in a cinematic in 2 minutes or less, where all the elites seemed sleepy.
Well, as far as we saw in Halo Wars 2, Jerome could fight a bunch of brutes (Stronger than the elites) in a closed space and kill them all, and he is just using the Mark IV, he's not even using armor shields, if you had read some of the lore you must know that with each new armor, each new generation of the mjolnir helps the user to have a better reaction and a better defense. And the reason they bring back them was because we rather the generation II and they want money (Halo Wars 2 is full of microtransactions).
The only community's sin is that they are so rude with 343 but nothing more.