Neither SE4 nor SE5 have totally random map generators, it seems to me. The first clue is that I have a game in SE4 with the exact same map layout as SE5. Also, many other games in both SE4 and SE5 have had that same map layout, and a picture of it is posted at spaceempire5.com
http://www.spaceempires5.com/en-US/node/244
I'm not the one that posted that, so when it came up as the random image one time I was quite surprised. The only differences I can see is that the warp points aren't all the same.