Ok after a day or so I'm seeing some rationale. Apologies for the wall of text!
From a simple perspective, Lomax is on marquee money and is not providing marquee player results.
If it's true that "with great power comes great responsibility", then with great money comes great expectations.
Flanagan leaked that stat about him being the 22nd best centre etc which is undoubtedly preparing Lomax for his imminent positional switch, and maybe preparing the fanbase for his departure.
Additionally, perhaps there is a perception that Lomax has unearned arrogance. There is nothing at all wrong with being arrogant, in fact it's often a huge advantage for a football player. However it must be earned.
For example Lomax will be inextricably linked to Hunt now, but Hunt has earned his arrogance. He's a multiple Test and Origin player (and winner), he's played umpteen finals matches and a grand final. He's the club captain. He's earned the right to be arrogant. He should be! Meanwhile Lomax has 2 finals matches 6 years ago and a couple of PM's XIII jerseys.
Then there's the Jack Bird scenario. Obviously I'd take Lomax over Bird at centre on a pure talent basis. But Flanagan is an experienced premiership winning coach, and I gotta trust his choice. Bird, also, is a winner. He's played Origin, and he's the only player on our books who's won a comp. He's also earned whatever arrogance he might display.
Zac is playing great football at the moment. His performances right now reminds me of the great Jason Nightingale at his absolute peak - 2010/2011/2012. Gypsy was 100% effort every game - chasing and leaping for every bomb, doing the hard carries frequently, wielding his physicality with opposing wingers, and of course, scoring tries.
Even at his brilliant peak, however, Nightingale never was in our top 2 most highly paid players. Probably barely cracked the top 5 in his career. Yet he had a premiership victory and 30+ Tests for New Zealand on his resume.
I also recall when Jason was 21 or so - and already 3 years into his NRL career - when a well-credentialled coach came into the club and shifted him out of his preferred position. He played on the bench. Occasionally coming on into the backline but mostly playing as a middle forward! Nightingale, didn't ask for a release. He stuck around and went on to become a living legend of the club.
Flanagan has said he'll look internally for a replacement before going shopping, but in any case we've got plenty of cash and while we've failed to land a huge target I'm pretty satisfied with our recruitment since Flanno took over and trust they'll make good choices with it