Well, the big question is what spells do you really want here from cleric SL 2?

Otherwise adding more spell levels just gives your better upcasts, so what spells are you upcasting? I think that’s the big difference between 4 monk and 4 cleric.

So if you are the kind of caster that’s sending out summon Draco spirit upcasting is a big deal. But if you are focused more on spells that don’t scale I think the power gain from just casting more in general is far less. Not that the monk provides a ton either, so my hunch is cleric 4 is better, but I don’t think the cleric spells add that much utility or value, so why not just take more Druid levels? Not that I mind an extra spiritual hammer flying around, but that’s the only one that comes to mind.