Congrats on your jounery!
I don't like switching out my main team, so I stubbornly ran almost all my playthroughs in a similar fashion you did! (Except for Rejuvenation V13 Intense, That version broke me). I'd often be running around with a team of less than 6 that consisted of pokemon I wanted on my main squad and HM slaves. It really makes me appreciate the potential of a lot of pokemon that I never thought I would add to my team. For example, my most recent Reborn team:
1. Charizard (Having dragon rage early on really helped with not having a full squad early on)
2. Whiimsicott
3. Lanturn
4. Shiftry
5. Weezing
6. Solrock
I never really thought of using Weezing or Solrock before, but after a lot of thinking and finally deciding to add them onto the team, I realized how well unexpected pokemon can round out a team.