(This experimental initiative system may be confusing but bear with me.)
Lydia crashes through a window and draws her weapons.
Spoiler
Breaking through a window would be a Fighting check rather than a Mobility check when the window is not open, but I'll let it slide this time.
Seamus splashes the wine onto Ecker's face, who loses one action and takes a -2 penalty on any checks that rely on vision (Archery, Awareness, etc.) until the end of his next round.
"Get him!"
Ecker starts loading his crossbow. (Initiative = Archery (1d20+2)[9])
Heimler pursues Seamus. (Initiative = Mobility (1d20+2)[5])
Von Richter also follows Seamus. (Initiative = Mobility (1d20+0)[1])
Seira and Rickel should also roll initiative. The skill you'll use for initiative depends on your first action you're going to take in the round.
Spoiler
I'm beginning to realize that the experimental initiative system may not work as well as I wanted, so I'll probably change it once this scenario is over... When I - the GM and game designer - have to start thinking "ok, how does this actually work.." there's a reason to change the rules. At least I rolled really badly, so you should be able to beat their inits.