On the OP.
I agree with your take.
As well as the definition of frum given by Yserbius.
However, ‘Yeshivish’ can also be used to refer a certain cultural type.
It should be noted, that frum is not the same as halacha.
Halacha just means that they are meticulous in their practice.
Frum signifies a deeper religious drive.
So we have three categories in each group. Member in good standing. Meticulous observer of halacha. and Frum.
It’s worth keeping in mind, that the slide that we notice as we look to the left is mostly on the first category. Since these three categories all blend, we try to talk about superiority. Much like how Lubavitchers may pontificate on the other threads.