That has bred familiarity and consistency with the players knowing their respective manager's style of play and having the ability to carry it out - and they are slap bang in the promotion race as we approach the business end of the campaign.
Here are my thoughts on the clubs in closer detail...
After 36 games last season Orient were in 11th position and had 51 points, but fast forward a year and they are nine places and 23 points better off, so they have done remarkably well to compete with some illustrious company.
They are the big overachievers in League One but have a feel-good factor, togetherness, round pegs in round holes and, after playing brilliant football all year long, are the top scorers in the Football League with 70.
There are plenty of unsung heroes, including right-back Elliott Omozusi and on-loan Hull goalkeeper Eldin Jakupovic, while Lloyd James and Romain Vincelot are the heartbeat of the side in midfield - but the front four take all the headlines.
The widemen differ in stature and the way that they play but they are equally effective.
Moses Odubajo on the right is fleet-footed, incredibly pacey and very direct; he is a youngster with no fear, who can go inside and outside, and really attacks the shoulders of full-backs and centre-halves, but he also backtracks and does the dirty work.
He has been a revelation and epitomises what a modern-day footballer needs to be, but Orient are blessed on the other side, too, with the pocket rocket Dean Cox, who I compared to a kitchen appliance on FL72!
The NFL had William "The Refrigerator" Perry but The O's have Dean "The Microwave" Cox and good things certainly come in small packages as far as their talented 5ft 4in winger is concerned, a man with dynamite in his boots.
Cox has a brilliant goal-scoring record - he got one in the 2-0 win over Port Vale in midweek - but has chipped in with 11 assists to boot, mainly due to his brilliant delivery from the flanks after coming in on his right foot.
Dean has often provided 18-goal David Mooney and 14-goal Kevin Lisbie, but Shaun Batt has come off the bench to great effect and Chris Dagnall, who Barnsley surprisingly let go, has been a major coup because he works his socks off and guarantees you goals at League One level.
I am made up for Orient boss Russell Slade who is a proper football man, really intelligent and excellent at harbouring a team spirit, and his team have kicked on again after losing three games in a row in February.
A lot of people would have expected the O's to falter after that but they have tremendous character, epitomised by the fact they have gathered 21 points from losing positions and that their away form (39 points) is better than their home form (35).
Orient will be there for the duration.
It's been a seamless transition since Mark Warburton took over from Uwe Rosler, with just one defeat in his 15 games in charge, and it just shows you what you can garner from continuity.
Mark has not got an ego so hasn't thought to himself: 'I'm going to make a change to show what I'm about' and has instead stuck with what served Brentford so well under Uwe for a good few seasons.
Warburton was part of Rosler's backroom staff and heavily involved in recruitment, so the players know him well, understand his methods and have performed exceptionally since his arrival.
Brentford have a big, strong and excellent squad, with great experience in 16-goal Clayton Donaldson, who is a threat as well as a workhorse, and inspirational midfielder Jonathan Douglas.
But they also have wonderful young players, with Jake Reeves, Adam Forshaw, Jake Bidwell, Will Grigg, and George Saville and they added to that group in January with Oldham centre-back James Tarkowski, a man I was surprised didn't get a Championship move.
Alan Judge has taken the place of the injured Sam Saunders - who will be kicking his heels alongside me in the studio on Saturday lunchtime - and the on-loan Blackburn man has become chief architect for the Bees, as well an amazing dead-ball specialist.
Brentford have the strength in depth to deal with any injuries and are perhaps best prepared to cope with the war of attrition that is League One because of their physical and dynamic players.
This could be a big season in the progression of the Bees, with a new stadium in the pipeline in addition to this promotion push, and I have been very impressed with the character they have shown.
They suffered double heartbreak last year - on the last day of the season against Doncaster and then in the play-off final against Yeovil - but it could very well be third time lucky.
There is only a piece of wafer-thin ham between the sides at the top of League One, though, so I will watch with interest to see what develops.