I generally see this play out as, one team trying to tackle the problem with a prototype and demonstration of tech. The other team just acquires as many people as possible and writes a bunch of documents. Then it gets run up the flag pole and the solution seems to be to go with the team that already has all the people.
Scenario A: Task a single team, staff them and let them do their thing. Cross your finger and hope they get it done.
Scenario B: Look across offices, org groups, whatever, and task 2-3 (sometimes more) teams with your task. Let them start work on it and get regular demos and updates. Eventually, pick a winner.
B looks very wasteful from the outside, until you realize that many software projects fail (like 50%). So more attempts give you a higher chance of success. Downside: Internal politics, waste, attrition from engineers throwing away code/busy work.
A is great if you can do it, but you're putting all your eggs in one basket.
A lot of times this is just bad org/bureaucracy though, but it can be done to great effect.
Disclaimer: Worked for a CEO with a large outsourced engineering base and several offices. Would see multiple attempts at different offices all the time. Eventually, grudgingly acknowledged there was a method to that madness. Trump also is famous for this (although his seemed more madness).
What actually happens is Scenario C - it doesn't arise from a top-down planner mandating it, it arises from middle managers (or their subordinates) further down the food chain each trying to grow their own kingdom, who all get the same idea at roughly the same time, and each build their own solution to the same problem.
During times of plenty, or if the top-level planner is only absent-mindedly managing that part of their org, the firm will be willing to tolerate these competing implementations, but during lean times, they cut, cut and cut and consolidate down to one winning solution.
A lot of corporate politics and strategy makes a lot more sense when you start looking at the personal motivations of the participants in it.