When you choose the ability to summon two whelps when setting the leader in a dungeon, and then place Old Murk-Eye, whelps are summoned each time his ability is triggered.
Same happens if you choose to spawns Defias bandits.
Every time the ability triggers, it spawns murlocs and bandits
This also happens with the Arachnid Whistle which spawns spiderlings when you play your leader.
What happened was Murkeye summoned 2 spideringly, then for each gold spent while his ability was active, 2 additional spiderlings were summoned. No murlocks were summoned at any point during Murkeye’s ability.
I also got the Stranglethron Commendation (summons 2 raptors when playing a beast) which behaved as intended, so no apparent interplay between a faction summoning extra minis and the Murkeye-leader summon minis boosts.