@WillLi
Your first point feels like it comes from a comparison from a generic shounen battle anime/manga where people can just train till their guard is up 24/7. Also it feels like a false equivalence that training directly equals to guard being up/never letting your guard down, which frankly is impossible to do so unless you've lived in a situation where it's life and death at every turn. Remember the fact that firstly he comes from and modern day, relatively peaceful world, and it's also Japan, where crime usually doesn't happen. Granted that he has taken lessons with his teacher about the art of archery (the killing version/warfare version), but that doesn't stop him from being relatively normal. In this case he's also pretty average at physical sports in Japan anyway. I don't think training at all would have helped the situation because of what
@Zacoras said:
suddenly a dickardly god teleport him to a battlefield without their consent and without too much information of was happening receiving a hard punch in the instant he reach the place, you know in that situation anybody was feel confused and no ready to figth
And in case the point is a bit rough, I'll elaborate it here too just in case.
1. Before this, MC and Bug goddess are established to pretty much hate each other, neither wants so much as to interact with the other, meaning MC doesn't expect Bug goddess to pull MC in to help her anyway
2. Aside from real world summoning, the Bug Goddess really hasn't been shown to directly send assistance to the hyumans, blessings are more of an indirect help
3. MC understands post status ailment trial that he has an unreasonably large mp pool, which also relates to how much magic is needed to affect someone of his caliber of magic. Given that he tested all of this with his followers, tomoe/mio/shiki having magic power far higher than 99% of the living beings on this world, he doesn't expect anyone to be able to teleport him in such a short amount of time without indication. To top it off, the only one which has shown they could is only Bug Goddess, which I've established in the above points that it's highly unlikely for her to do so
4. Due the earlier points, MC does not expect a sudden teleport from Bug Goddess to send assistance anywhere, and certainly didn't expect to be separated from his followers given that he's used to having at least one of them (tomoe/mio/and new!shiki)
5. As he is suddenly separated from said followers in a location which he doesn't recognise, his guard is already up, but the shift to battle mode hasn't been made (still cautious)
6. Unexpected attack from someone who suddenly vanishes from his sight to attack him, he'd be dead in a situation where if he actually doesn't have his guard up (flying head)
And through all of this, do you still think any amount of training would suffice for a surprise attack of that caliber. Note that in this case it's not about training, it's about reaction to Sofia's actions. You pull any trained master martial artist into this situation, then expect them to cope with Sofia's speed and come out alive is really borderline fantastical here.
Also about your point with MC being calm because he's been in worse pain? I'm really confused? Where did you get this? The same chapter literally states it's been the worst since mio, and he didn't need to deal with it because he had help and was taken care of later. If he was having a mental break down, he wouldn't actually be analysing the situation this calmly to escape from Sofia/Lancer. Regarding your call to MC taking time to form a plan before retorting, that's also a bit questionable. He's attacked and the first thing he does is try to understand why he's in this situation,then he goes and tries to figure out why he can't communicate with his followers, following that after one brief retort, he decides to first deal with his injury and gleam out more information. He opts for a diplomatic approach before trying make a plan up to escape. I don't think you understand what a person having a mental break down behaves like, well to be fair I haven't had one, but that analytical behaviour isn't one that a person with a mental breakdown would go through.
So hopefully I've broken down why "train more" isn't really effective in this situation. The threat right now is that he has to face off against an enemy who has demonstrated speed and power to be able to injure him, while dealing with his bleeding injury from the earlier surprise attack. All the fights so far have been abnormally skewed to his favour, provided it was a straight up fight with no tactics involved. There's a difference between a surprise attack and a surprise encounter, which I see you've also falsely equated to each other. The fights between him and Tomoe/Mio have been surprise encounters and not attacks, where neither took the initiative for a surprise attack and instead only knew that the other was present when they both met for the first time.
The point with Subaru was talking about the initial encounters,not the week he spent dying to prepare, MC doesn't have an X amount of time to prepare for an encounter ability he doesn't know that exists, hell that's something only Batman would do. So Subaru spent the time preparing for the same situation, while you expect Makoto in X months to prepare for situation which is highly unlikely to happen before this point in time.
Sorry it's a bit long, but thank you for coming to my TED talk.