My problem with "you can do this, but within reason" is that it got me burned in a previous league. I got kicked out of a franchise for going no huddle while winning 14-0, 2nd quarter. The rules said "no huddle is allowed, but don't abuse it". It was the first time I used no huddle on consecutive plays all game. Why did I do it? Because my opponent came out in dime vs strong I while he was losing losing on 1st and 10. I argued that most teams would love to force a timeout with that personnel grouping in the NFL and most would do so, except that nobody in the NFL actually comes out in dime vs strong I while trailing by 2 scores because it's extremely poor play.We do/did allow RC (rocket-catch), nano blitzes (don't get out of control on nanos), motion, audibles (some guys do/did Peyton Manning audibles), player substitutions (SS in as LB, OLBs as DEs, TEs out wide as WRs or FBs, etc), and others but within reason.
But the commissioner interpreted that as abuse and I was kicked. I was upgraded to a permaban when I attempted to inform other members about what transpired ("undermining the league") because the opponent I played quit the game twice on me and said person was close with the commish. I pushed for heavy penalties on that person since quitting once in that league was clearly supposed to result in immediate suspension while quitting twice was perma-ban. Considering that person tried to lie and say I quit and that I took photo evidence to show otherwise, it was a very sticky situation. The commish considered it best to silence me by banning me off his forums/chat and kicking me out of the league.
Now, while it's unlikely that your league would be run that way, any time you leave in subjective rules it opens itself to interpretation and ultimately due to human nature, bias.
The obvious glitch plays are good bans but I will simply never join a league that has interpretive rules like "do this but within reason" again.
Remember, madden players are not NFL coaches. They usually don't have the experience, virtually never the decades of coaching knowledge, or the realistic control a coach would have. They DO have the ability to micromanage everything on-field players do. Even with the engine limitations aside, those realities *vastly* change what the realistic best approach to a game is. This is ALSO true for player opponents. Madden defenses are not built like NFL defenses. Because of that, it's hard to fault an offense for doing something repetitive when it's working. Every NFL team would run 1 play all game if it would work, but it doesn't work because NFL teams adjust.
That's why the only things I'm willing to work with in sim leagues now are EXPLICIT rules, things you can and can't do that are clearly described to players and easily enforceable through simple video clips or even pictures (as opposed to recording whole games or going by word of mouth).
I can't make your decision for you and ultimately it's your league and you have to run it best as you see fit. However, I do suggest you think about a more explicit set of things banned, such that players do not get retroactively penalized based on interpretation of whether or not they did something just BARELY too much. When you have clear lines and accessible reporting mechanisms, enforcement has much less potential to turn into a nightmare or cheat-kick someone who didn't actually violate rules...and it's also much easier to pin violations on people who actually cheat.