The South Sydney Rabbitohs have extended their era of Charity Shield dominance in what will be their only true hit out ahead of the NRL season, defeating the St George Illawarra Dragons with a second half blitz at Kogarah on Saturday evening.

After running out a mostly reserve grade side in an unofficial trial last week against the Sea Eagles in Gosford, the Rabbitohs were closer to full strength as they clashed with the Dragons, albeit missing Latrell Mitchell and Cody Walker who both played in the All Stars game on Friday evening in Townsville.

The Dragons, on the other hand, are looking to springboard into a new season under the new management of coach Shane Flanagan, and had some impressive signs in the first half before making big changes for the second.

Here are the key talking points from the final trial on Saturday's slate of games.

Does Zac Lomax need a chance at fullback?

Unfortunately for the Dragons and their fans, the rocks and diamonds start to Tyrell Sloan's first-grade career continued on Saturday evening against the Rabbitohs.

While the youngster, who spent most of last year in first-grade following Cody Ramsey's illness diagnosis, had plenty of nice moments in the game where he finished with five tackle busts and 121 metres from 14 carries, he also had some moments he'd prefer to forget, both in terms of ball handling and defence.

Shane Flanagan has made it relatively clear that Sloan will be getting first crack at the fullback role this year, but there is also doubt surrounding his ability to stay there all season.

That, in short, is because Jack Bird has become a centre, which shuffles Zac Lomax out to the wing. The talented centre is one of the Dragons' most dangerous attacking weapons, and there is little secret that in an ideal world, he would probably be playing in the number one jumper.

He has the talent to do it as well, and could find himself getting a crack there next week as Shane Flanagan assessess his options.

Cody Walker's heir apparent revealed

Jack Wighton may well never be a first-choice five-eighth again.

The widely-held consensus is that he has been signed to play two years of centre, and then take over from Cody Walker in the number six jersey when he retires.

The issue with that is Souths had signed young Jye Gray from Queensland before they signed Wighton as the apparent successor to Walker.

And the former under-19 Queensland representative proved exactly why Souths had been so keen to get him to the club against the Dragons, being one of the best on ground in the eventual 28 points to 6 win.

He was involved in plenty of South Sydney's attack, running the ball superbly and looking a real danger everytime he found even the smallest bit of space.

He didn't take much in the way of kicking game responsibility, but he didn't have to with Dean Hawkins and Lachlan Ilias running the show there.

Watch for Gray to impress at NSW Cup level over the next 24 months before putting his hand up for an NRL jersey.

Who plays five-eighth for the Dragons?

Speaking of battles at five-eighth, and the Dragons have a two-up race to determine who will partner Ben Hunt in Round 1 and beyond this year.

After signing Kyle Flanagan early in the off-season, the Red V added Ronald Volkman late, only for his contract to never be registered. They then went out and signed Jesse Marschke from the North Sydney Bears, with the NSW Cup five-eighth of the year adding substantial depth to the Red V.

And while Flanagan has received glowing tributes from Hunt during the off-season and is expected to start there, it's a very real argument that can be made that Marschke actually outplayed him during the Charity Shield.

Both however got involved in the game, running the ball well and looking threatening at various points.

This is a battle which isn't over. I fully expect Flanagan to receive first shot in the six, but don't be surprised if this position flips back and forth more than once during the season itself.

Sean Keppie has won a spot at the Rabbitohs

Of all the Rabbitohs' forwards playing last night, maybe the key storyline to follow was the performance of Sean Keppie, who has made the switch from the Manly Sea Eagles during the off-season.

A hard-running middle third forward who has plenty of NRL experience under his belt already to go with being an ex-junior State of Origin player for the Blues, Keppie hasn't quite hit his true potential during his time on the Northern Beaches.

But that looks like it could be all about to change after he put together an excellent performance against the Dragons in the Charity Shield, with Keppie looking fitter and meaner than he has in previous years.

By the time it was all said and done, Keppie looked to have well and truly won himself a spot in South Sydney's rotation, running for 156 metres from 17 carries and holding up his end of the deal at the defensive end of the park.

While Tevita Tatola and Thomas Burgess are the key front rowers, and others like Davvy Moale and Shaquai Mitchell will push for minutes, Keppie could be what South Sydney need to add to their engine room.

Fitness, fitness and more fitness at the Red V

The Dragons have had one glaring issue in recent seasons - fitness.

Of course, there have been other problems, but the bottom line is you simply can't be a successful NRL team if you're not fit.

It's something a handful of players have acknowledged, it's been admitted by ex-players who are now at other clubs, and it's a point which has been rammed home repeatedly by new coach Flanagan.

And while fitness isn't an overnight fix, it's clear the Dragons have spent a mountain of time working on just that during the off-season, with the club's main squad looking fitter during the first half last night before the majority were taken out of the game.

Leading that charge were the Couchman brothers, who both had excellent games and could well have put themselves into the mix to both be included for Round 1. Of course, Toby was likely already in the Dragons' best 17 after impressing at the back-end of last year.

But it wasn't just the youngsters. The likes of Jaydn Su'A and Michael Molo both looked better than they did last year, while Jack Bird also had some nice moments at centre.

It's hard to judge given the quality of opposition, but the Dragons should be in a better standing than they were last year after a full off-season under Flanagan.