Druid and Cleric are truly different classes. Nature Domain gives a Cleric a few Druid-specific spells, but that is not enough to turn a Cleric into half of a Druid (far from that).
Classes are not like divisions of labor, divisions of magic, different departments of a single university, different types of sports, etc. Different classes are different, yet they share a lot of things. It is really due to historical reasons that they happen to have evolved into the classes as we know today, into the classes as adopted and implemented by this game. In turn, this game will inevitably also affect the further evolution of these DnD classes.
"shadowheart for example should have the evil list. cause why on earth would shar give her the ability to cast guiding bolt?" --- Spells are just like weapons: they don't have alignments. We cannot say a dagger is evil or a mace is good. We cannot point to any spell and say that the spell is evil/good/neutral. Actually, in this BG3, the concept of alignment has been dropped. When we say Shadowheart is good or evil, we are commenting what she does (based on player choices). The game itself won't judge Shadowheart based on the concept of good or evil or neutral. We, as players of this game, do. The game itself has no concept of good or evil or neutral. You may kill Shadowheart a thousand times in the game, yet the game won't judge you - a player who has been doing that.
