Whats really more strict
Gun must be unloaded and encased (impossible to use if you can't carry)
The use of a gun is prohibited. (can carry, just don't use)
I don't think this falls under the preemptive law at all.
Yes it does fall under the preemptive statute. You have the right to Open carry and the fact that there are more city parks than state parks makes the ordinance unenforceable.
What the heck does the number of parks have to do with anything
If you had a state park within your city limits the city could impose an ordinance banning fire arms within the state park that is all.
No such ordinance is needed, OCing on said state park would be illegal under state law, would it not. A state park is a state park regardless of weather or not it's in city limits.
The fact that there are more city parks than state parks period would infringe on your 2nd amendment rights in that it would be more restrictive to the areas in which you could carry a fire arm.
Please cite your source for this