I agree with almost everything that has been said here, sorry that I am two weeks late to the conversation but figure I would throw in my $0.02 for anyone else that stumbles across this topic.
Enscape and Lumion are currently the best software solutions to what your are experiencing with your team. I would assume that you are already at least trying out Enscape, if not, I would suggest trying it out before Lumion. If you still feel like you need more quality from the renderings after trying Enscape, Lumion will get you a little further.
Enscape will make you the most agile in most cases, but as Virgil says, you do have better control over the rendered result with Lumion, especially with materials. There are some odd quirks with Lumion, such as a fixed 16:9 ratio for all rendered output aside from 360 panoramics, and the interface obscures a lot of the power that lies within it. The tools that Lumion has for populating a parking lot, sidewalk, landscaping, horizon break, or being able to show something in glass reflections are quick and intuitive. Enscape has a little bit of this but is not nearly as easy or quick to use.
Really the best situation would be to equip your designers with more than one tool since there are pros and cons with each, and there is nothing to say that you couldn't use both Enscape and Lumion on the same project for different needs/phases.
This is all subject to change in the near term as well with the proliferation of realtime raytracing. I feel that we are getting closer to having a realtime engine with the quality of offline engines such as VRay and Corona. The main thing holding it back today is that the tools to get there are still pretty rough and require quite a bit of model prep work/clean up. It is a tight race between Unity and Unreal right now to get there first, but we may see one of the specialized packages such as Enscape or Lumion or Twinmotion beat them to it.