These assume heavily armored feat as well as weapon master. For arcane cleric, take green flame blade and booming blade for bonus cleric cantrips for arcana cleric. Key off wisdom.Too many shorthand so I have trouble following... What's gfb and bb?! And a Cleric doesn't get a second attack, what do you mean by 'second target'?!
And if you want to be a melee Cleric, you're better off with someone who gets Divine Strike (and even there, from 5 to 8 you'll suck).
Weapons Master is a bad feat that was badly designed that nobody ever needs.
greenflame blade targets two targets. Strength damage applies to a melee attack. Given potent cantrips for arcana cleric, you add wisdoms bonus to damage.
cast spiritual weapon and spiritual guardians if you wish.
the potent cantrip is as good as average divine strike roll.