It's not broker - but which mm
If you want to enter/exit position - use the AX
That's what I do
For RETC the ax is either CDEL, ASCM, MICA, or PUMA - depending on situation.
As for the size of your order, MM are permitted to hide lots of OTC so you don't see their true hand 1/2 the time.
What i do is when I want to accumulate I wait until big ask comes then take it out. Or I rarely sit on bid as I don't want people see my hand. What I also do is use AON orders, and market makers hide those :-)