At school I learned the following foreign languages (in that order): English, French, and Russian. In each language we started with simple words and basic sentences. With every new chapter in the respective study book new words were introduced and the sentences would become more complex. Step by step grammar rules would be taught and we would be exposed to all the irregularities in each language. I very much doubt that anything would have been different if we had to learn these languages in a different order.
I am now trying to teach myself Thai and all the study books follow the same principles as above.