This is a decision you have to finalize after considering all the factors. Understandably, some parts do get so complex that there is no option left but to break them up into several, manageable parts. However, this comes at the expense of added labor costs and time. Plus there is always a chance that you could have manufactured a single, more precise part in a properly undercut injection mold. So, make sure that you have exhausted all your options before considering a multi-component approach.