It is not very clarifying.
It is somewhat clear that number of spell slots follow DnD rules, so that caster levels are added together, with slower progress for non-pure casters like arcane thief. I.e. cleric 3/wizard 3 is considered level 6 with regards to spell slots (have 4x1st, 3x2nd, 3x3rd), and cleric 3/arcane thief 3 is spell considered level 4 with regards to spell slots (have 4x1st, 3x2nd).
However, what spells can the cleric 3/wizard 3 prepare? Clearly they can prepare 1st and 2nd level cleric spells, but what about 3rd level cleric spells, since they have access to spell slot level 3?
And in case they can do so, it is actually a problem? Or does the action economy keep things in check?
We will get answers soon.
