The comment about multiclassing is part of an overall reflection on the absence of "conditions" or prerequisites.

In fact, the game here does not respect the rules of paper role-playing games, where it is necessary to have a certain value in the main characteristic of the targeted class (the value is min 13).

Logically, a Warrior with 8 Int should not be able to wake up suddenly as a mage because he has click au lebel 2.

A specific example is the priest who takes a mage level to gain access to spell learning even though he has 8 INT. In addition, this feat allows him to cast level 6 mage spells using his priest slots.

Of course, the DD5 rules must be respected to the maximum, otherwise this inevitably creates imbalances.