That's very interesting.
It seems like there's not much incentive for the incumbent players to undercut one another. If I'm Johnny BOI, I could cut rates for <60% borrowers, but AIB will follow suit if/when they see their business bleeding. We're back to square one in terms of market share, but now the market is that much less profitable. It's a plague on both our houses. We're better off f̶i̶x̶i̶n̶g̶ matching prices.
On the other hand, if I'm Johnny Pepper or Johnny Deutsche Bank, I have no existing customer base to devalue, and every incentive to cut the legs from under the incumbents.