I mean seriously, you can see the problem with 343i in so many ways.
The fucking hideous weapons and enemies, not to mention the overall game design and thinking about Halo
The difference is stark but it also has a lot to do with how video games are made these days.
You either need a very strong creative lead, who is able to protect and guide his vision of the game or you need perhaps even a subpar team that works really well together.
Both are not as common as you may think. Bungie had a great team of some of the best in the industry, which is extremely rare.
Studio leads spend more time communicating and planning the work for the different art, environment sound etc. teams than actually working on the game.
And only at the tail end can they really see how everything comes together. Pulling in a lot of talent also isn't a guarantee for success if the chemistry isn't there.
In fact it can work against you in case there is a competition of sorts.
Ubisoft is one of the few studios which has a very fine tuned process for big productions such as these but their 'template' is showing its age.
Other studios like CD Projekt Red, Nintendo, Kojima Productions, Remedy etc. rely heavily on their strong creative leads or teamwork.
Nintendo basically hands their creative leads such as Sakurai, all control.
Microsoft over the years collected people who can hit production deadlines and salvage projects (like Rod Fergusson) but they don't have very talented creative leads.
Or people in those roles long enough to really create a vision. Sony's set-up works decently too, combining their creative talents with a few tech support groups.
Microsoft is trying to address this problem by either acquiring sub-par teams (Ninja Theory) or strong creatives (Double Fine / The Initiative) but it'll take a while before results.
Now Microsoft has once again called in Rod to do the thing he always does, which is to turn a troubled AAA+ project heading towards a 4/10 into an 8/10 or 9/10 by making the right cuts.
Microsoft is still feeling the pain from gutting their first party teams and infrastructure over a decade ago.
These are the projects in the open that we know about, just imagine the stuff they couldn't salvage over the years.
It also doesn't help that they turned HALO into this corporate thing with brand directors, franchise directors etc., which is a joke considering where the franchise stands at this point.
HALO needs to be a good FPS, first and foremost. All this 'platform' bullshit won't last a year if the player base isn't there.