@Greyhood Hard to say without knowing the full batting roster... but based on what's said,
most likely the team has only three good batters including the MC... so he sweeps the two likely to get on base, and insures that even if they get outs instead there's a chance to score in the first inning, which puts the most pressure on Yuuri and such. In baseball, like war, demoralizing your opponent can be a huge advantage... putting them off-kilter can make them hesitate, choke, or rush. It messes with rythm. This can potentially make it more likely for other players to get a hit as well, though that's not the point (though as you just saw, it helped MC get a clean homerun).
The real point is to have the best chance to score as many runs as quickly as possible both to demoralize the opponent, and to get to the "mercy" rule as fast as possible, to reduce the opportunity for the dogs to score, and make sure he doesn't overly strain himself by trying to pitch a perfect 9-inning game (an extra 12 batters at minimum to have to go through compared to getting "mercy" in the 5th). As a side note: Demoralizing is undoubtedly part of why Wolfsmund kept going despire their massive lead in runs in that first match we saw. Either that or the author did it without thinking about the rule.
The real point is to have the best chance to score as many runs as quickly as possible both to demoralize the opponent, and to get to the "mercy" rule as fast as possible, to reduce the opportunity for the dogs to score, and make sure he doesn't overly strain himself by trying to pitch a perfect 9-inning game (an extra 12 batters at minimum to have to go through compared to getting "mercy" in the 5th). As a side note: Demoralizing is undoubtedly part of why Wolfsmund kept going despire their massive lead in runs in that first match we saw. Either that or the author did it without thinking about the rule.