Scaling instances questions

Hello everyone. First of all thanks everyone who was envolved to Axoniq conference taken place in Amsterdam in september. Really enjoyed speakers and conversations during cofee-breaks!
We with our team keep on tuning and evolutioning our project and have a question.
Thanks in advance for possible answers!

Suppose I have an Axon application with several microservices.

And one of the microservices is scaled up to 2 instances.

I have a command that creates aggregate.
After I have a command that updates aggregate.

Simple question what if first command executes for long time and which instance
will handle second command ?

Or e.g. first AggregateCreatingEvent is still in process but there is already updating command has been dispatched? Which instance will be responsible ?

And what happens if first command failed when handling in an aggregate ?
Will there be any issues with handling second command ?

All of this kind of clear when keeping in mind just single instance of an application. But when it comes to scaling some questions occurs