Don't use the level 4 tengu for c3 sites, sleepers can web you super far out and you will get rekt with a 300 dps tank.
Depending on the site you're running as well your cap stability may need to be better to counter the neuts.
If you're going off this guide:
https://docs.google.com/spreadsheets/d/17cNu8hxqJKqkkPnhDlIuJY-IT6ps7kTNCd3BEz0Bvqs/pubhtml#
In a C3 the largest incoming DPS on a site is about 1400 but you'll probably want to avoid that since it's a relic site anyway.
If you stick to the others the most you will ever have to tank is around 800 DPS
[Tengu, c3]
Ballistic Control System II
Ballistic Control System II
Caldari Navy Ballistic Control System
Damage Control II
Republic Fleet Large Cap Battery
Pith B-Type Large Shield Booster
EM Ward Field II
'Copasetic' Particle Field Acceleration
10MN Y-S8 Compact Afterburner
Adaptive Invulnerability Field II
Cap Recharger II
Heavy Assault Missile Launcher II, Scourge Rage Heavy Assault Missile
Heavy Assault Missile Launcher II, Scourge Rage Heavy Assault Missile
Heavy Assault Missile Launcher II, Scourge Rage Heavy Assault Missile
Heavy Assault Missile Launcher II, Scourge Rage Heavy Assault Missile
Heavy Assault Missile Launcher II, Scourge Rage Heavy Assault Missile
Medium Rocket Fuel Cache Partition I
Medium Hydraulic Bay Thrusters II
Medium Capacitor Control Circuit II
Tengu Offensive - Accelerated Ejection Bay
Tengu Defensive - Amplification Node
Tengu Propulsion - Fuel Catalyst
Tengu Electronics - Emergent Locus Analyzer
Tengu Engineering - Capacitor Regeneration Matrix
This fit does 713 DPS to battleships at around 30km, the ones thar orbit further out you can switch to javelin which drops you down to 475 DPS but 60km+ range. You can always burn towards it and switch to high damage ammunition also.
You'll be using CN scourge for the most part which is 607 DPS @ 40km
Tank on it is 855 DPS omni which means you should be able to do every anomaly with no problems
It has a +29.8 GJ/s capacitor delta meaning you can tank the neuts of any site as well (not the relic or data ones ofc)
This fit requires a 1% power grid implant also since it's 0.25 power grid over (sadface:()
I also took cost into consideration and it comes in at a cool 607m, should take around 3 hours to pay itself off.
Obviously this is also capable of doing level 4 missions.