Having used both, these are two different products, not attempted clones of each other.
At their most basic level, Dynamic Procedures is a Map informational overlay; SmartCharts are terminal areas charts (IAPs, SIDs and STARs). Intended use is different. SmartCharts are a potential chart replacement. As Garmin says in some of it's videos on the product, SmartCharts satisfy FAA requirements (at least in the Part 91 world). Once the offering is complete, you could conceivably fly with only SmartCharts without either FAA or Jepp terminal charts. Foreflight's Dynamic Procedures, OTOH, are not. They may start from the same data source, but as FF specifically says on the Sidebar, you are expected to
This is not a huge surprise. FF is part of the same company as Jepp. If FF said you could replace Jepp Charts with these, that would be the surprise.
One of the more practical differences is the depiction of weather and traffic. As a Map overlay, with Dynamic Procedures, it's there. SmartCharts, as somehting separate from the Map, do not (currently?) display those. But, unlike Foreflight, Pilot does split screen and, from playing with that, the SmarCharts are so decluttered that I think they work well side by side with the Map (so long as you leave the vertical profile off).
These are two different approaches, but with every turned on that can be at any one time, you can get an small idea of the basic differences between the two.
It will definitely be interesting to see a full side-by-side comparison, but I'm not sure if Aviation Consumer is the place. I did a few comparison articles in IFR and it was always difficult even when trying to show only a single feature (I did one on custom holds). A bunch of words don't do it justice compared to a video, and in this case, you'd probably need 30 pages to cover something that could be shown better in a video flying even one procedure with both