Trades are a really big thing that need to be looked at. There really needs to be a new system for doing this. How often in real life do 2 teams sit down, put equal amounts on the table, and make a trade right there that day? I would have to say like never. The closest it gets to this is probably day 2 of the draft.
Head coach had a step in the right direction with their system. At least there was some competition going on with other teams so a market could be developed for some players or picks where if a lot of teams wanted him he might have increased value.
It was to rushed and hurried though, no team in real life is going to say "All of you other GMs have 2 minutes to offer me trades and after that I will take the best offer". These things should last for days of game time with multiple trade talks going on at the same time. Also, there needs to be a minimum limit to what the team will take in exchange for their player or pick and if that is not met then no trade goes through.
It needs to be similar to the head coach on where you make an offer and then wait to see how it sits with them but maybe something somewhat like their free agent thing where you make your offers then advance to the next day and look at the responses.