If you sit down an think about it, the 2 additional workers isn't really all that big of an advantage, at least if you buy the starter pack II when you are IA or Global. (And I'm not sure it's even offered to players in earlier ages.)
In the IA you can have 14 workers. Since most of the upgrades you'll care about take 4 workers (in the Global Age, even things that used to take fewer workers, like Towers, now take 4), that means you can do 3 standard-sized upgrades simultaneously while still leaving 2 workers free to harvest cider so you can run the all-important Training Blessing. So, suppose you buy the starter pack II and now have 16 workers to play with. You could do 4 standard-sized upgrades now, but only at the cost of locking yourself out of being able to harvest cider until one of your upgrades finishes. And with Global Age upgrades taking in the neighborhood of two weeks, that's a LONG time to do without Training Blessing. Or, you could stick to the 3 upgrades you could do before, leave 2 workers to harvest cider, and use the 2 from the starter pack to upgrade - what? Those extra workers from the starter pack would essentially only be able to upgrade farms, caravans, and oil wells.
I don't know about you, but my farms are still medieval-level and I still have more food than I know what to do with. Caravans and oil wells are more useful; I wouldn't kick upgraded ones out of my bed if I found them there. But I almost always have higher-priority things for my workers to do. So, if you have some money to burn, by all means get the starter pack and get those marginal increases to your gold and oil income way sooner than I will. But for all the pay-to-win aspects of this game, I am not too worried that people buying this starter pack will have a big advantage over free-to-play cheapskates like me.