Hi, the short answer is that group games involve putting one or more elements into a set number of categories. Here, we have 4 of each, so we will,have 1-1 relationships between the architects and the projects. It isn't possible to have more than one person on each project.
A longer and likes better answer would be that this game is similar to group games. We have elements of placing things together, which we do in group games. We also have elements of ordering, which we see in linear and multi linear games. Ultimately game types are an artificial framework that we impose. It's a very useful framework, but it's not perfect. Many games include elements of both grouping and ordering, and this is one of those games.