How can we connect the fifth installment with the previous games in the series?

That's why you created this thread, right? To connect everything... heroes and times change... we've already gone through 5 eras... and these eras are almost all described thanks to all the parts and expansions... just global cataclysms... and in our time, this is relevant... if you understand what I mean... and I think we have the same idea...

Added 2 minutes later
Moreover, it seems to me that the world is one, but there are many civilizations... in this case, five... but in addition to this, there are also travels through time... some heroes confirm this... in principle, this explains why the development of civilizations is the same...