Oh no, I don't think it's bad! If you need those characters and you need them named, you need them. That's it. There are readers who are going to be confused no matter how many named characters you have per chapter, and there could be so many reasons for that, from having problems remembering names to the names being foreign (the names in your book are!) to the readers reading the book on the train and being not able to focus (this happens to me sometimes). Remember, those who let the names wash over them were the ones who
didn't tell you about it, right?
Maybe there were more of them?
Ha! I have a huge, huge cast of named characters, probably well over 100 (haven't counted yet, will do that when editing), some of them change their names in the course of the story (the MC changes his name four times), and not a single name is an English one. I'll probably thank a few of them, but not many; some of them are there to deliberately make the scenes crowded, and if my 1st-person narrator/MC knows and remembers them, he's going to name them. ESPECIALLY if they are women.
I don't sweat it if the names start with the same letter, but I do try to diversify them by using names of different length and melody (Suma and Akashi, for example), give them descriptors (Little Sada), or put the title, occupation name, etc. next to it. If the character is important, I will introduce them with a bang or at least with confetti, meaning that they will have their own scene when they appear for the first time. If there is considerable time gap between the scenes in which they appear, I'm not above reintroducing them – since my MC is quite literally telling his story to someone, I can and will do the "I dunno if you remember her, but she was the main courtesan in our house" trick quite shamelessly. Have I conquered the issue? Just gagged it and put in the cupboard? I don't know yet; I'll see during the editing.
I have read your book <3 and I didn't have a problem with the number of characters*. I have generally good memory when it comes to names, though. But... Readers complain. Reviewers complain. There will be complaints whatever you do. This is one of the minor ones, I think... Don't let it take too much of your time. If it helps any, I have 10 named characters in my 1st chapter. Maybe 11. Okay I'll shut up now.
*or with anything