To much website task to maintain various website looses your focus on getting the right results. When you are assign to maintain website it is best to develop 100% rather than multi-tasking in developing various project. Doing multi-task can drain your energy and resources. But each developers has his own different stroke to getting the results want he wanted.
The problem of to much website to maintain is time consuming. The best way is to delegate easy task to your team so you can focus on difficult projects. This requires the level as a lead developer both social and technical skills.
Take for example if you have 10 website it would be best to take one task at a time to finish each website applications. Or do you think getting multitask in 10 different website can get better results? The answer is no.
Moving a head in developing 1 website at a time is best practice if you are working alone rather than working in multitask that are unfinish and unsatisfied.
Again it is always best to work as a team in developing multiple website because their are task that are easy that you can delegate so you can do difficult task that only few knows.