Why are there only two options for leaders in the standard selection(solo vsAI mode)?

[すなお]

After installing the DLC, I am playing in solo mode. In AI matches, if I set the leader selection to "standard", I have to choose between only two (possibly random) leaders. Is it not possible to select from all leaders?

[noctilucus]

"Standard" indeed proposed a random selection of 2 leaders to pick from. If you hover your mouse over the button, it will show you this explanation.
With "draft", the game makes a random selection of 6 leaders and players take turns picking 1 of those 6.
"Random" completely eliminates any choice from the process.
So far, a completely free choice is not an option, but I don't mind as this avoids that you would always pick the same and miss the variation in playstyle that comes with a different leader.