Are Azumarill and Lanturn good defenders?
Both have low CP (so low CP decay) and high HP. I live in an area with extremely high gym turnover, and trolling attackers with uncommon defenders might keep some attackers away.
Azumarill CP 1166 Bubble/Play Rough
Lanturn CP 1693 Water Gun/Hydropump
Lanturn CP 1560 Water Gun/Thunderbolt
Lanturn CP 1553 Charge Beam/Thunderbolt
Answers
"trolling attackers with uncommon defenders might keep some attackers away."
Nah. You think these two would make trainers give up? You're also worrying to much about what to put next... just slap them in gyms. You already stated the high gym turnover. Even a maxed out Blissey would fall to a dedicated attacker with adequate resources.
My area is getting to the point I should use 1500 cp and less and actually do better. It takes a while for my teammates to pile mons in, much less opponents bothering to tear down. Thinking of a Sneasel leader, something that doesn't decay and that I want more candy of. It'd get wrecked by fighters, so maybe my wife put in a level 20 Alakazam to get her coins. Today was Saturday and should be a big raiding day...about two dozen people on Discord all day in the northern half of a big city--lucky most decent players and Entei doesn't take many. I was willing to use more than my free pass, but couldn't get more going besides today's 1872 catch
Azumarill has lower CP (slower motivation loss), and much better defensive movesets.
Lanturn has higher HP (comparable to a Vaporeon), but worse defensive movesets and lack of type coverage against grass.
Azumarill's best defensive moveset is Bubble/Play Rough or Ice Beam. Rock Smash is fine too. Both charge moves keep Dragonite away, though Play Rough is better due to STAB and shorter dodge window. Azumarill may not be able to get a Hydropump off.
Lanturn's best defensive moveset is Charge Beam/Hydropump. Thunderbolt may be better on paper, but it would barely tickle ground types. Hydropump would do SE damage to ground types. Lanturn also has enough HP to get a Hydropump off in most battles, with Charge Beam's fast energy gain.
Both share a weakness to Venusaur. Venusaur also resists all their moves, except Azumarill's Ice Beam which Venusaur is weak to.