Sabre vs. Mig 23? Hmmm

Maybe I do not have a good grasp of the BR placements in battle, but can someone possibly explain why 3 times tonight, Ive been in a Sabre (CL mk 5 varient) and been on a team and enemy composed of Mig 21s and a few Mig 23s?
I would appreciate that explanation. Maybe I dont have a good understanding of how planes are placed in battle, but I will say CL mk 5 is BR 8.7.
It just so happened I had Silver Lion bonus activated, and so LOL, it was very disappointing, although I did manage to survive, with no kills…Perplexing to me, but maybe Im just not “getting something”.

There are many kinds of MiG-21 and MiG-23
And there are some of them which are in low BR.

MiG-23 which you faced was the MiG-23BN, which was designed for ground attack.
In this game, no missiles either.

I should probably look, but game off now. And what BR do they sit in? I will guess 10.3?, pretty good flight performance?

Because I have a lot of mig21s, and they seem to all have good flight performance, even in their BR?

And the Mig 23?, what are there drawbacks against a Sabre, this is kind of interesting.

the mig23BN is 9.7 and has poor performance due to its early wing design, and while the mig21s at 9.7 and above are good, they are mostly balanced