Both Samiʿa and Karuma may be frequently intransitive, but they differ in vowel pattern and characteristic meanings:
FeatureSamiʿaKaruma
Patternفَعِلَ يَفْعَلُفَعُلَ يَفْعُلُ
Common meaningsFeelings, conditions, defectsEnduring or inherent attributes
Exampleفَرِحَحَسُنَ
MeaningRejoicedWas beautiful
Shared semantic territory is not enough to move a verb between conjugational classes. Check its attested perfect and imperfect.