Sorry if my post title is a bit misleading but that was the only thing I could think of as a title. Now to the main point.

My uncle has four different businesses registered with different names and and into different areas of business (events management, architecture, diesel supply, sales of phones and accessories).

Now he wants to incorporate everything in a group to house everything. He recently paid a guy to help him design logo, complimentary cards and letter head. This guy(designer) designed separate logos for each of these businesses and also for the group. Same with the cards and letterheads. I mentioned to the designer that since the group now houses every other business, there should just be one brand for the group and all businesses under the group should also carry the same brand. The designer on the other hand thinks every business should have its own brand since they are into different kind of business.

Which is more professional as regards brands?

One Group, one Brand, one Identity.
#my2naira

i support lightheart's stance on this. One group, One Brand, One Identity...If it a group with multiple ids, confusion will set in and also it will be difficult to manage several brands. Another point his, your Uncle might want to incorporate several business ventures later, yet another brand? No, I dont think so. I did something similar for someone here on Nairaland sometime ago in one of my thread, I think Abase or thereabout, and I think it was okay, it's better to have a brand house all of that.