Michigan CPL holders have the unique benefit of not permit matching (obtaining licenses from other state in order to add to the reciprocity/recognition list). A Michigan CPL is valid in every state that recognizes a carry license. The only places it isn't valid in is in states that do not recognize out of state licenses. There is no magic formula to gaining reciprocity for the most part. It helped that Jennifer Granholm and Mike Cox were two Attorney Generals who aggressively sought signed reciprocity agreements with states that required such agreements for recognition.
To simplify this, this is largely due to the following three reasons.
1. Michigan will not issue if you are a federally prohibited person.
2. The validity of a CPL can be verified 24 hours a day, seven days a week.
3. Michigan requires training with live fire.
Michigan conducts the equivalent of a NICS check prior to issuance. There are some states that will issue to people even if they are federally prohibited from owning a firearm. Michigan is not in this category; therefore, we score points when it comes to background checks. We even meet the requirements for recognition with Washington State; which requires strict mental health reporting requirements.
Another issue that isn't so much of an issue anymore is the ability for out of state LEO's to verify the validity of a permit. Until recently, many states lacked this ability and places like Virginia will not honor a permit if they don't have an easy means to verify it. While most states now have 24/7 verification, Michigan was one of the earlier adopters of this, in fact, back when Michigan was "may-issue", CPL info was placed into a state database that was not difficult for authorities to access if need be.
Finally, Michigan has training with live fire, this is a situation where having more restrictions means for more reciprocity. This is an absolute requirement for states like Nevada where they will not recognize a permit unless live fire is required as a condition of issuance.
It is important to note, that having a liberal issuance law does not mean reciprocity/recognition would drop like flies. In fact, if Michigan got rid of the fingerprinting requirement and the laundy list of misdemeanor disqualifiers, we wouldn't lose any states that we currently have.
If we ever get a friendly governor who is willing to sign pro-RKBA reform, this issue should be looked at. I would recommend a multi-tier permit system, similar to Idaho and North Dakota. These states have opted to create an additional license for the purpose of reciprocity while leaving the older system in place in effort to avoid the predicament of passing more gun control in order to gain more reciprocity.
I would recommend a Class 1 CPL where there is no training requirement and the minimum age of issuance is 18 and the issuance guidlines mirror the disqualifications of a Purchase Permit. This permit could even be valid for 10 years or for life.
The current CPL would become a Class 2 CPL where all the current requirements remain in place with the exception of the laundy list of misdemeanor disqualifiers, a decent compromise would be to whittle down the massive list to a misdemeanor crime of violence in the past 5 years where there was intentional damage or harm to a person or property. If a person had this on their record, then the CPL could become "may-issue" in their case until the 5 years have lapsed. This is how the state of Mississippi handles this issue and they seem to do just fine.
If we ever have a friendlier climate in Lansing, there is no reason we can't liberalize the CPL process while still having the most recognized carry license in the U.S.