Not me.
In the same way that Fighters and Paladins of every description normally get Heavy Armor proficiency but are denied it if they arrive there by multiclassing, even though heavy armour is quintessentially a fighter-ish/paladin-ish lifestyle thing.
Allowing it for (some) Clerics would imply that those clerics were somehow more fighter-ish than Fighters and that doesn't fit the default concept.
However, in both cases you can multiclass and still get heavy armour proficiency but it costs you a feat.
Of course, you could create a campaign where clerics ruled and reserved heavy armour training for the chosen few (i.e. themselves) and denied it even to single-class fighters; then you could house-rule it how you liked.
From what I've read, you are the one pushing a house rule unless you can somehow prove that abilities aren't granted according to class levels for archetypes. And I very much doubt that you can.
So your viewpoint is contradicted by the rules until you prove that character level applies to archetypes. You can house rule as you like if you feel domain abilities seem to be tramping on your idea of the fighter and paladin being the only ones that should gain heavy armor when multiclassing. I wouldn't expect any official support given the PHB is written and the designers tend to rule in favor of the rule as written. And archetypes all use class level, not character level. Not a single archetype uses character level.
I even had this clarified for warlock invocations. All the level requirements for warlock invocations are based on class level, not character level, even though it does not explicitly state this. I doubt any archetype abilities of any class will be ruled otherwise including cleric domain abilities.
Last edited: