You are complaining about a symptom of not having enough experienced people onboard. Juniors will make a mess, regardless of if they try to use something existi

You are complaining about a symptom of not having enough experienced people onboard. Juniors will make a mess, regardless of if they try to use something existing or reinvent the wheel. Knowing when and what to reinvent is just a function of having worked at more places and for long enough to see what is good and bad with the existing solutions.