Understanding German grammar rules is not at all an issue as one lecture is enough to cover one topic and it’s usually very straight forward and it always makes sense but, to use every rule that one learns, one needs to know the actual article of the noun.
To know how the Lokal and temporal preposition will change, you need this information. To change bestimmter articles to personal Pronomens, you need this information. To make a simple Akkusativ sentence, you need this information. You need to learn german with Artikels. This is important!
Well don’t stress out too much, it’s tough but not impossible and with a little concentration, interest, and practise, you’ll be a pro at it.
Course outline itself and the book we use it also designed to ensure that Artikels are part of the learning.
See my friend here solving her grammar exercise like a PRO!

Jaweriya