What's confusing isn't the naming but the inclusion of different architectures in the same "generation". Given this, the naming is better than any previous naming.
I think that the architecture's digit place is in a logical position. The first digit roughly corresponds to release year, and sure, that's only a marketing digit which helps OEMs sell. Putting the architecture here would have been informative from the customer's perspective, but it would be hell for marketing, as for example Mendocino would be matched to a 2019 family.
The second digit as a performance marker is in a good place, as it's what the buyer wants to know. Architecture affects single-threaded performance, and in that respect a 5600U would be faster than a 5700U, but on the other hand for multi-threading the 5700U is faster than the 5600U. I don't think it would make sense to place the architecture before the performance digit, as then a 4 core with low clocks could be placed before an older architecture 8 core with higher clocks.
So it makes sense to relegate the architecture digit to third. It's better than not putting it there at all, which I think would have been more confusing. So sure, it would be better to have the same architecture for the entire lineup, but if that's not the case, then what AMD has chosen is as good a solution as any.