When I was a young tenor, C4 would hurt. I couldn't get it aligned right. Eventually, I would start moving into the primo at Bb3. According to Miller's books, I'm not a tenor. "Oh yay! I'm a baritone!" I look at the baritone book. "Oh no! I'm neither! :'( " I ran into the term "zwischenfacher" which is a female who can sing both mezzo and soprano roles. I asked if I could be the equivalent. He said only women can. However, I might MIGHT have the kind of male voice which can CHOOSE if he wants to be a tenor or baritone. This was so awesome! I wasn't "stuck" like everyone else! I could actually pick what I wanted to sing!!! I sang baritone AND tenor arias. Whenever we picked out art songs, I could usually sing the low, medium, and high keys, but one would work "best" with my voice. I was inexperienced at the time, so I can't effectively recall how he chose. BUT I do remember the key he picked is what felt best.
So, from 18 to about 22/23, I would constantly get asked what my voice type is. I would sing a tenor song and get asked if I'm a baritone. I would sing a baritone song and get asked if I'm a tenor! So confusing as a young man! Ultimately, I wanted to be countertenor, but that's another story! My teacher at the time abhorred that sound, so he kept avoiding that topic with me.
Vocal Coach, Dr. Karen McCann, suggested to me that she thinks it may be because I have a fuller lower extension that most tenors don't have. Both my private instructors in college said that the person who knows my voice best is the one who's been listening to it the longest.
Ultimately, I gave up trying to figure out my fach. It'll come when it comes. I just sing whatever I want! I think Jessye Norman said it best, "Pigeon holes are only comfortable for pigeons." This came from a very talented woman whom I admire! I sing Zueignung by Strauss because I heard and saw one of her performances, and it made me cry!
My advice, "Don't get stuck singing one style." Or anything for that matter!
Know yourself! Grow yourself!