Is Securing MS M&A Execution (UK) for SA hard?

First of all, thank you for your help during this recruiting cycle, I secured some weeks ago an offer at MS London and wanted to ask you some questions regarding to the group selection:

1) How does group selection work at MS? Do I have to network with the teams I am most interested at?

2) Any tips to better position myself?

3) Is there a lot of competition for M&A Execution?

4) Is it true that M&A Execution positions the best for HFs? Mostly interested at exits to Citadel, P72, Elliot, Man and Millenium

I understand that this group may have rough hours, but is it exit wise is the best? If I can´t secure it, which other group should I am for?

For context, target undergrad, target msc and previous regional IB experience at a decent bank (BB/EB)