In many languages conjugations are defined by the fixed template (the template itself can be large). In Korean, Japanese and other agglutinative languages the template is virtually non-existent (Wikipedia seems to give a 7-part template [1] which looks quite absurd for native Koreans---it should be considered a "common" regularizable subset of what people actually say).

[1] https://en.wikipedia.org/wiki/Korean_verbs#Finite_verb_endin...

eh.... haber isn't really "to be" at all. "to be" is pretty well covered by estar and ser. The only case for haber to translate to "to be" is existential, and pretty much only conjugated in the third person when used that way. Otherwise it's just an auxiliary verb, where its usage parallels "to have" in english (but not indicating possession, which is tener). It's basically just a glue verb.