does reference passing guarantee order of execution

[snarkysparky]

If a block gets an invoke reference from another block, is it guaranteed that the block passing the reference will execute first ?

In the image the flow will always be left to right.

[RTSLVU · Accepted solution]

Yes, all input conditions must be met before a VI can execute. 

So the VI before it must finish before the VI after it can even start

Most of us use the Error Cluster to force sequential execution, but any wire will work.