"...a salmagundi of affirmative defenses."
Grounds for denial of intervention of right (or, in the alternative, permissive) did not have to be extensively described by the court -- the decision is reviewed for abuse of discretion in light of the record.
No abuse of discretion of denial of intervention of right by citizens attempting to stop cell-phone tower on church steeple where it is apparent that the existing parties will attempt to vindicate the specific statutory protections that the citizens intended to raise; the litigation strategy of the existing parties doesn't enter into the calculus.
No abuse of discretion in denial of permissive intervention, as existing parties would raise the smae issues, the putative intervenors had no cause of action under state law, and it's really important to build cell phone towers quickly.
T-Mobile Northeast LLC v. The Town of Barnstable