Don't just pull numbers out of thin air, there's no value to that. I don't know of anywhere in the game that could guarantee the 1500 kills per hour you are suggesting you can get away from WWTH. It gives around 40-50 kills per minute @ at least 20XP each. If you want to compare that with anything else, provide empirical evidence, otherwise it's just worthless speculation.
The bounties you mention require giving additional Xp are great for that when out and about, but they often require you to go out of your way to do other things, some several minutes away via sparrow - 2 minutes driving is a guaranteed 100 kills you could have shooting hive, or 2000XP. If you sack these off, there's still the time taken to collect and junk them which again is all dead time you co9uld be spending gaining a guaranteed return facing the suicidal hive.
WWTH is boring, it's tedious, but it's guaranteed to level up characters and gear fast, and I'm saying this from experience and any YT video of hive farming shows you how quickly the cycle flips. Add in a black wax idol every 10 minutes while the results screen is up and you're farming around 15000-18000 glimmer an hour easily as well.
The only way you can prove me wrong and show your method is better in terms of XP-per-hour is to record your gameplay for a minimum of at least one full hour and provide the evidence that you have a reliable and better method of gaining XP