Organization+Strategy
Visigoth:
Famous for having successfully sacked Rome in 410 AD and been part of the cause of the beginning of the fall of the Western Roman Empire. This war was successful because of King Alaric who demonstrated he was an exceptional military commander. Alaric was able to besiege Rome because of his strategic plan of sending what what could be describe as a “Trojan horse”, as well as his experience and knowledge of the Roman military strategies. The Visigoths offered slaves to the Roman Empire, but sent skilled warriors who attacked the city from the inside and opened the gates for the rest of the Visigoths. They showed that through good military leadership, strategy, and knowledge of how the enemy operates are key factors of war. However around the begging of the 6th century to early 8th century the Visigoths became part of Hispania after having been defeated by the Franks. Unfortunately, not much is known about the organization of their troops. But it's known that they planned strategic attacks by using the geographical areas to their advantage. They would use the swaps as a strategic way to slow down their enemies if the geographical location allowed them to do so.
Vandals:
The Vandals got their name through the Romans who labeled them as a “barbarians” and "usurpers" because of their success at sacking Rome. The first early accounts of this group describes them as an unorganized “barbarian” group of Germanic tribes who sacked Rome with no real strategies or self-control. Throughout time they experienced being conquered and being conquerors.The Vandals made Carthage their capital and were established in a large part of North Africa. This was a strategic move since it allowed them to take control of Sicily, Sardinia, Corsica, and many other territories along the Mediterranean coast. However, due to their location in Spain, there was constant battle between the Vandals and Visigoths which took a toll on the Vandals. Not much is knows about their army organization, but they did have their Kings as military commanders who fought alongside their units. However, there is documentation of when Rome regained Carthage which shows how the Vandals were outsmarted in strategy and battle when it came to the battle of Ad Decimum in 533 CE. During this battle the Vandals tried the strategic act of cutting the Roman army off from water supplies to scout them out but this battle was ultimately the Vandals' lost. Additionally, most of the accounts on the battles are often unclear since there isn't much documentation, and if there is it's usually in favor of the Romans. There is proof, however, that they had a strong and well organized navy which allowed them to keep the Romans at bay for a time, in fact when the Romans regained Carthage they did so by trying to evade those units.
Present Day:
Spain's military today consists of various ranks. Today, the Armed Forces are formed by units in land, water, and air and the commander in chief the king of Spain. While that is indeed similar in the cases of the Visigoths and Vandals who were commanded in battle by their Kings, in Spain today, the King requires the agreement from the Prime Minister, who is also known as the President of the Government, to take some form of military action. Additionally, while the Visigoths and the Vandals had kings or high ranked officials as comrades in war, Spain's military today get orders from the King with the approval of the Prime Minister about what battles they will engage in without them at their sides. Instead they, similarly to the Romans, plan the strategies and decide what, when, why and where will the forces be used while staying safely in the cities. Furthermore, as the Visigoths and Vandals are part of history, some of the way they approach battle and/or the reasons for why the lost their battles are important information that has allow the leaders of today to learn from their ancestors' victories and failures to implement that knowledge in today's world. However, today the Spanish military had to adapt after events such as WWI, WWII, and the Cold War which pushed them into a commitment with global organizations such as NATO. While the Vandals didn't really commit to anyone, the Visigoths did commit to treaties with the Romans throughout history, and while the scale at which they had to commit was different, it's still signs tha cooperation is learned and necessarity throughout time.