IMO, there is far too much emphasis, or rather obsession, in GMs trying to upgrade their rosters by making trades. This leads to too many trades in MFN, certainly as compared to the NFL, where the most active days of trading are during or shortly before the draft. Otherwise, there are few, if any blockbuster trades ever made in the NFL. And it is the sheer number of trades in MFN that calls to our attention the need to discuss the issues in this thread.
I think the reason for so many trades rests on a fundamental misunderstanding by GMs of the value of overall player ratings as it relates to other factors that contribute to success, i.e., winning games and competing for championships. The result in MFN? There is far too little focus on actual game play, i.e., actual detailed game planning, which requires schemes and complimentary personnel (not necessarily elite players). For my money, I'll take my chances against a roster filled with elites with a roster filled with players whom I rate in the 70's, but whose average overall default ratings probably hover in the 60's.
Words of advice to newbies:
Don't mortgage your future by trading high draft choices, even for elite players, unless you realistically have a chance to compete for a championship after the trade. (I don't know how a newbie can make that assessment until after playing at least a few MFN seasons.)
Don't fool yourself into thinking that one player will "pull you over the top".
Build depth on your roster by signing free agents or drafting players in the lower rounds who have skills that compliment your schemes. (It's frequently your subs that will give up or make the big play - more so if you take advantage of their skills and minimize their weaknesses by taking into consideration the formations and circumstances under which they are likely to play.)
Remember, even a zero rating for a particular skill doesn't mean a player has no skill in that category. Even the slowest WR in the MFN would probably run a 5+/- second 40 yd dash. So, his speed and/or acceleration bars in MFN would be low. However, if he has excellent route running skills, excellent hands and courage, I guarantee he will make some plays for you. Especially when you need a couple of yards on short yardage plays, irrespective of the skills of his defender.
By the way, the need to trade for elite players can be diminished if MFN makes it harder for GMs to stockpile them. After all, which elite players in real life do you know who would settle for being second or even third string AND being paid less than fair market value to boot? Exactly none would be my guess. So, how do we do that?
First, restrict extending contracts for any player (whether drafted or signed as a free agent) until just before the last year of his expiring contract.
Then, peg the amount a player demands for the first year of his extended contract bonus and total compensation equal to the average bonus and compensation paid in the last year of his expiring contract to highest "X" number of players within "Y" number of points of his overall default rating. (X and Y to be determined.)
The amount so determined can be increased or decreased by the length of the proposed extension (longer terms cost more, in absolute terms, both in bonus and total compensation). Other factors that could affect the amount demanded could be (1) the age of the player (older, more experienced, players should cost more per season (but also get shorter contract offers)) and (2) the player's relevant statistics, e.g., the number of plays played during the season before, the number of tackles made, rushing yards, etc., which reflect the player's relative importance to his current team and other teams in the league.
Anyway, implementing something along these lines will likely put upward pressure on the amount paid to retain players and ultimately make the salary cap more meaningful. Thus, I would expect more players, especially higher rated veterans, to hit free agency. This would reduce the number of trades and place a higher premium of drafting well, which is the case now in real life.