most of the IS units in prototypes are up-teched variants apart from the Dola (WoB tech stolen by the CC), Pendragon, and the industrials. the clan side has mostly new units - Stinger IIC, Incubus, II, Beowulf IIC, Mad Cat III, and Thunderbolt IIC.
for me, periodization is a slight problem. Clan Invasion and Jihad run 3049-3062, and 3067-3085, respectively. going 3085-3140 (latest 3145/50 intro date for a non-superheavy quad) stretches coverage a little long. But it's not nearly as bad as Succession Wars that has 500 years of history all speaking in the present tense.
smartly selected, you could use the units to tell the story of the rise and fall of the republic. or at least get to the blackout