What do you mean by to start? If you meant if it will work then yes, it will work with some degrees of efficiency. If you are asking if it would work really well, then no. Pillar upgrades make a huge difference in speed decks. I don't understand why you would care about the number of upgrades, you would eventually work towards upgrading the entire thing right? The vast majority of decks are quite a bit better after upgraded which is the whole point of upgrading. If you are upgrading a deck with the intention of not completely upgrading it then why bother with the deck in the first place? A good enough deck deserves to be completely upgraded if you want to use it and a not good enough deck is not worth upgrading at all. So, to answer your question in the OP, no you don't need to upgrade the pillars, it can still function, but upgrading it will make the deck a lot faster and if you are not going to exploit the full potential of this deck there's no point to upgrade any of it at all.