I'm not sure I understand what you mean, maybe you could draw a template of it?
I assumed the first two stages were slave society and feudalism because you start at the bottom and move up, with time starting at the bottom and progressing upwards.
Anything like this maybe?
I noticed that a connection were missing at the end of two feudalism stages. I've fixed it but I'll wait releasing the update a bit to see if there are any more problems, so there won't be too many small updates.