Hi and welcome to Binky Bunny! Yes, in the US, holland lops are the smallest lops, around 3.5 pounds. Before your bunnies reach 12 weeks of age, you will need to separate them to prevent pregnancy and fighting which can occur when they reach puberty and the hormones come flooding in. Hopefully, you will be able to separate the hutches and put the ends back on to make them into two pens again. They also will have to have separate play and exercise time until they have been spayed and neutered and a month or so has passed. Once you have put them into separate pens, they can be in the same room, but don’t have the pens touching each other, because rabbits can manage to mate through cage bars.
I assume the bunnies in your avatar are the ones you are getting. They are very cute!
Here is the link to the thread regarding uploading photos: https://binkybunny.com/FORUM/tabid/54/aft/144934/Default.aspx