LEM was not added as a brand because they only had a few (very few) mixers/products that can be classified as DJ gear, the main focus of their brand was always (semi) pro audio gear.
For Dynacord that is something simular, this is a pro audio brand that makes lots of pro-audio equipment. They made some DJ mixer models but they got discontinues pretty fast due to the 'success' of sales of these models unfortunatly.
Same would go for Soundcraft, but their few dj mixer came out in an era that can be seen as the 'beginings' of the rise of DJing, hence the fact this brand is added.
I can add brands but then would need to have at least 2-3 products complete filled in (modelnrs, images, product specifications). If the info is available I can add the brands so items can then be added onwards. I try to make a solid start for each brand myself to give a good example.