Realistically you can get citizenship with 2-3 years of legal residency. If you do not get legal residency, then you you likely will never get it. Rubilar for example has many cases that have nearly a decade of no progress due to this missing fact of legal residency. So, if you want success it is imperative to be legal here.
In addition, other facts of your life will be taken into account by the judge. The judge has a LOT of discretion, so don't think that knowing someone who got citizenship with X, Y, Z circumstance will mean you will if you have the same circumstance. Other factors that will play into the decision is your relationship with argentines (kid, spouse here), whether you own a home or have a business, and whether you work and earn money in argentina (versus working remotely, etc).
The fewer facts showing you have sufficient attachment to argentina, then the more the judge will use discretion. If the judge does not see sufficient evidence you have made argentina your home, then your case will become paralyzed. For example, Rubilar has paralyzed cases with people with argentina kid, cohabtiting with an argentina spouse, here for 10 years with local income, etc. The thing most all of have in common is they did not have legal residency.
So, if you want citizenship get legal residency. If you have that, then you don't need a high priced lawyer just submit a few docs after 2 years here and you will get it most likely.