My style is to have the roads towards victory as hard as possible for our MC, so keep that in mind when listening to my suggestions. I will assume that he did not have any OP treasures or talents, as well as guessing that he did not have any special connection with any of the gods. So, no one to guide him, no special training methods to help him rise faster than others. Now, we knew that he is talentless as well as a slow learner, so, in my opinion, he should not change his class to restart and continued to improve his mastery over his swordsmanship.
Yes, that is ultimately the plan. So for the first restart (second life), MC should further refine his swordsmanship instead of trying to multitask like the first time where he tries his hands on swords and then magic. As spoken, MC gets to groundhog like Zorian for limited tries before he dies off for real. So continuing on from your opinion, I am guessing either MC trains until he reaches advanced (assuming the four tiers, beginning, intermediate, advanced and expert) where he dies once more or somehow gets his hands on a cheat like the black white lotus from Reincarnated Swordmaster, eat it and then die. Because frankly, imo even if MC spends his entire lifespan on swordsmanship, he will at best only touching advanced due to his immense lack of talent. Fyi, the MC here is build to die in the hands of someone even cheatier, because the MC in my story is actually built on a "one scene" villain from a xianxia I read long ago. Long story short, the villain's grandfather and uncle murdered the entire clan of the story's MC, so MC murdered them. The villain's father was pissed (actually not that pissed cuz he considered his father and brother to be worthless, but FACE) and so decided to hunt MC. He got his entire sect to hunt the MC and ended up MC killed them all, including the villain's mother. Villain grew up like a typical xianxia MC, trying to get revenge from the monster that is MC and garner aid from a bunch of people. In the end, the villain died, not really though, as the MC turns his corpse into a puppet and sealed the living consciense of the villain into the puppet and then ordered the villain to hunt down all his friends and family, those that helped him, and kill them gruesomely. At that time, I felt hilarious, like wtf, there are no good guys lol. *Insert Barney the dinosaur theme song* "I kill you, you kill me. Let us all go on a killing spree~ With a great big whack I rip your head in two, won't you say you kill me too?~"