Advanced Wave Spawn with multiple enemies -2 Datatables... Wave and Enemy

Hey there, on this tutorial Casey makes a really nice spawn system -> with datatables

One negative part, it only spawns one of a kind enemys. he said you could do it :

two tables for spawning. One of them would hold the different types of enemies you have in your game. The other table would be for waves. So in the enemy table you might have rows for “Ogre”, “Goblin”, “Troll” (columns being their stats) and in the wave table your rows would be the wave #'s and the columns would be the amount of each enemy. …then arrays

Hey I ve worked on that topic but came not further then this …

How can i get now the Data -> cause if i do "make array" its a Struct Array but how can I convert it into a Integer Array.
Or is there another Way to get the needed Spawnnumbers?

Hope someone can help me
For a bigger Picture: