Andrew,
I was referring to the MLO desktop for sync'ing. To answer your question, yes, you can make the task in MLO and assign it in Outlook. The process would be:
1) Create task in MLO
2) Via the Desktop, sync task(s) to Outlook
3) Assign task to user in Outlook
4) Can re-sync with MLO periodically
MLO supports either uni-directional (MLO to Outlook, Outlook to MLO) or bi-directional sync'ing and you set up which tasks to sync. I have a dedicated view called "Sync to Outlook" which is a subset of my work tasks I'm working on I want in outlook. I do that because I use an Outlook add-in called Taskline that will auto schedule tasks to compete. Kind of like time-blocking but letting the computer do the scheduling.
It does require you the utilize Outlook to assist with task management but that mostly around communication and, I'm assuming, you use Outlook regularly.
Leigh