Who should handle or supervise your project? Architect,builder civil or structural engineer

There is always a confusion in choosing who to handle or supervise a project especially for a newbie property developer.
Questions have been raised severally on who should handle individual projects, however building types will determine who you should use as an arrowhead onsite.
The larger your project, the more the numbers of professionals and technical people you are expected to have on your building site.
For smaller projects like 2 bedroom bungallow any of these professionals are okay for it, there is no need to have more than one professional on site for small projects.
A young architect, builder or structural/civil engineeer can on their own supervise any bungallow with little or no supervision. But when it is a storey building especially a multistorey building or duplex, then you need the input of the architect not only as the designer but also on site as the overall
supervisory officer, in some cases they may supervise on secondary role basis.
The builder is trained to execute every line of command represented on sheets of paper by the other building professionals, therefore a builder is more at home on a building site more than any other professionals, because that is his major occupation. He can enter the roughest parts of site and see to it that job is done properly and he likes to be physically involves most time.
An architect has very strong ability to detect an error, he is trained to be a perrennial critic, he sees the building as his baby and ready to protect the baby jealously, the pride of an architect is to see his design come out well executed and beautiful.
Now take the architect as the mother of the child (the building), the builder as the nanny. The nanny does all the dirty works, work hardest and may be closer to the baby than the mother. But the mother happens to be the one that conceived and bore the child, so she is more protective of
the child, she has a vision of how the baby should look like in the process of growing, she monitors her and anything shot of her expectations will not be welcomed. she may have to shout at the nanny when the baby is not well fed or taken care of.
The architect surely did the work of conceiving and drawing plan of the building, but he may not neccessarily have much physical impact but technical in actual construction, but he knows exactly how the building should look like and what he wants, so he won’t settle for less.
The structural engineers job concerns the stability of the building, so we may take the structural or civil engineer as  the peadiatric doctor that monitors the health of the baby and prescribed drugs to sustain his or her life. This is also the function of a structural engineer to the building. Architects likes to fantasize and come up with out of the world designs, it takes the engineer to look at the design and relate with the architect about the structural disposition of the building, if its possible to build with the technology and expertise available or not.
An Engineer makes sure the building is healthy by prescribing the right reinforcements/iron rods to stabilise the building and stop it from eventual collapse.
From the illustrations above it is important to have at least two of the major three building professionals mentioned above on your site especially when your building is a storey building or more complex structure, afterall two heads are better than one.
The structural engineer and the architect could take a supervisory role whereby they come to site to make sure their designs are followed strictly and give them opportunities to pass down further instructions and incase of adjustments or redesign, they will be in best position to know what to do.
Whatever case, one of them should be on site preferrably a builder.
For higher storeys and more complex structures, the architect,the building engineer/builder, the structural/civil engineer, the electrical engineer and the mechanical engineer are suppose to be on site. (the mechanical engineer deals with the plumbing works).