Depth Chart Adjustments

I was reading a month-old thread that was about depth charts. From what I got out of it, depending on which defense you run,, your depth chart should be changed accordingly (3-4, 46, 4-3 etc)
What I am wondering is, what determines these changes? Stats? How the specific defense is used accordingly? Help me out here haha. And also what would be Vikings depth chart with the different defense strategies? Here is the previous thread link: http://forum.madden-school.com/madden-defensive-strategy-f91/ne-defense-depth-chart-t13371.htm#141707

i like to adjust my depth chart to my style of play, i run a 4-4 so my slower still talented LB's go inside while my faster backers go outside, just lil things like that, if you drop a certain position more than others put your best zone guy there, if you play alot of man then put your best man corners to start, these are just some examples of things that people do to tweak and adjust there depth chart.

What exactly do you mean by the linebackers inside and outside? And how do I know what my best man corners are?

each player has special ratings like speed agility awareness, then they have attributes that are specific to there position like for RB's trucking and juke and spin move, for WR's catch, catch in traffic, for QB's throw power, throw accuracy, short, deep, and medium accuracy, just stuff like that, on the depth chart you can scroll over to the right to see these attributes.
ill give you an example of what i do, i like my slower guys inside cuz it takes less time for A gap blitzes to develop, and it takes more time for heat off the edge to get there so i want my faster guys on the edge cuz when i bring heat off the edge its gonna take a lil longer then when i bring A gap heat so i want my fastest players there, i play alot of zone so i pay attention to my DB's and LB's zone rating, not man coverage rating, these are jus some examples of adjustments you would make depending on what type of player you are.