Its all to do with the electrical charge of what ever is causing the haze,Hence different hazes respond to the different finings.
If one fining is not effective there is every chance another one will work.
The two part finings are however very effective on the vast bulk of wine hazes.
There are however some very difficult hazes such as pectin and iron or copper haze which don't respond to finings the cure for these is pectolase and various chemical treatments.Such as citric acid.
The latter hazes often come from using metal implements when making the must.
Plastic or sanitized wood utensils will avoid these sorts of problems.
Metal pans unless high grade stainless or coated with non-stick Teflon should also be avoided.
Even poor plumbing in some houses can be the cause of the haze,Requiring the use of bottled water to avoid problems.
Pectin haze can be detected by adding meths to a small sample of the wine,If strings form in the sample the presence of pectin is indicated.
Unfortunately hazes in wine is a big,big subject.