First time Arborec infantry production question

I understand that space docks cannot produce infantry, but let me pose a quick hypothetical question. Let's say that on my home system all I have is a single infantry and my space docks; how many infantry am I able to produce? 1 or 5? Basically does the production value stack despite being different units? Thanks in advance, I'm going to be playing the happy space plants this weekend and thought this might come up.