Yes, becuase it wasn't the wars but the assertion of Prussia as the pre-eminent military and political power of the region that allowed the unification of Germany. The wars were just one of many possible ways to do it. When Bismarck was sent to represent Prussia at the Frankfurt parliament formed during the Revolution of 1848, there were two predominant theories concerning the very popular idea of German unification. Grossdeutschland (Greater Germany) was a unification involving the Austrian Empire, including all its non-German subjects. Kleindeutschland (Small Germany) was unification excluding Austria. Bismarck was a fervent advocate of Kleindeutschland, and in the process soured relations with many German liberals and Austrian dignitaries.

In hindsight, Bismarck was correct about the infeasibility of Grossdeutschland. There were two major powers in Germany, and any Grossdeutschland would have to involve a power sharing agreement between them. When had any diumvirate in history ever succeeded? There are examples, but they were so few and so foreign to 19th century Europe that Bismarck cannot be blamed for his failure to consider the example of the cooperation of Orhan I and his brother in the 14th century Ottoman Beylik. Bismarck's writings make clear that he viewed confrontation with Austria as inevitable long before becoming Minister-President of Prussia, if only to prove which one of the two German powers was on top.

The Danish war was a political scheme to enlarge Prussia - which was Bismarck's chief early goal (he did not have a "master plan" for unification at the start) - that happened to provide an opportunity to confront Austria as well. Bismarck was unpopular almost immediately after taking power as Minister-President - he had insulted the liberals in the chamber by denying the founding myth of Prussian liberals, that the people, not the King, were responsible for driving Napoleon out of Prussia - and needed a foreign war to distract public attention. This war, being over a German issue, would force Austria, which saw itself as the leader of the German Confederation, to join should Prussia make the first move. This in turn meant the Prussians and Austrians would have to divide the spoils of the war, which also meant that Bismarck would force war by failing to come to an agreement.

It is not clear exactly when the "gears started turning" in Bismarck's head which led him to this conclusion. Immediately after the Prussian army achieved success, he denied to the Duke of Augustenberg, the legitimate ruler of the territory Prussia had captured from Denmark, the right to rule autonomously and proposed to his Austrian counterpart that Prussia and Austria partition the captured territory instead. Austria, in a great blunder, accepted, and the resulting dispute over who got what led to the Austro-Prussian War.

Following the defeat of Austria, it became clear to the South German rulers that Prussia and not Austria would be the future guarantor of their safety. They all concluded alliances ahead of the 1871 war with France. Bismarck still needed a way to formally integrate these countries into Germany, having already annexed most of Northern Germany - contra popular belief, Prussia's peace terms in the 1866 war were not "moderate" as they involved the annexation of many of Austria's allies. He decided the people would be the key, as German unification was popular and if the Kings refused to integrate following a great rise in patriotic spirit, their people would likely overthrow them. To generate this spirit, Bismarck engineered war with France by starting a dispute over the Spanish throne which had recently vacated. The popular exhileration of victory all but forced Bavaria, Wurttemberg, and Baden to accept annexation as their rulers were powerless to resist the popular sentiment.

Were all these wars necessary? No. Only the Austro-Prussian conflict was somewhat inevitable if one wanted to create a centralized Germany instead of a federation. Would France have gone to war with Germany had Bismarck somehow annexed the South Germans without first defeating them? Likely - owing to the hubris of the French military and government in 1871. However, it just so happened that the way events played out, war was the most convenient way for Bismarck to achieve his aims. It was uncertain that Bismarck, with his confrontational relations with the legislatie majority in Prussia, would have survived had there been no Danish war. It is also uncertain how he would have provoked conflict with Austria without the dispute over the lands taken from Denmark. It is finally uncertain how Bismarck could have easily annexed the South Germans without a war against France to inspire German national spirit. There was no "necessity" in the French and Danish Wars in the sense that not fighting those wars would not have prevented the unification of Germany forever. It just so happened that there was no clear path to unification without them.

This gets to the core of Bismarck's political acumen, and an assessment of his own character that he would have agreed with based on his correspondance. For decades, German liberals had been dreaming of unification, imagining all the most wild and fantastic scenarios in which all of Germany would voluntarily come together, or perhaps the people would force the hands of their princes. Bismarck's achievement was in figuring out a way to actually do it. He needed a good enough excuse to kick Austria out of Germany (one which didn't look like naked aggression), and needed to provoke France to make the first move and declare war on Prussia to stoke German national feeling. Together, those would give him the stick he needed to strongarm all the German princes into signing over their sovereignty.

Sources:

Steinberg, Jonathan. Bismarck: A Life.

Kassner, Kenneth. Coercive Diplomacy: Otto von Bismarck and the Unification of Germany.

Showalter, Dennis. The Wars of German Unification.

Kissinger, Henry. The White Revolutionary: Reflections on Bismarck. <Dated, but still good information on some of Bismarck's political motivations for his diplomacy, including the influence of his opposition.>

Deighton, Anne. Winds of History or the Acts of Men? The Unification of Germany.

Rathbun, Brian. The Rarity of Realpolitik: What Bismarck’s Rationality Reveals about International Politics.