Why should connect phase not be top down? Will there be any impact if it is top down. if there will be no impacts why we have not done it in the same way as build phase

I am aware that why build is Top-Down.
Just wanted to know why we cant have connect phase in the same fashion. Will there be any impacts?

In reply to prashanth.billava:
The phases other than build are using a simple depth-first traversal. See this thread