Faction Warfare LP payouts make no sense

TLDR; Just do Small plexes in T1 frig (or cheap destroyer if you want to be posh) and you'll make more LP whilst risking less than in any other ship.

So on occasions I can't be bothered roaming around for fights and just want to chill and farm some LPs in FW. I decided I should at least take a quick look at how to be semi-efficient whilst doing so.

As this is eve, the EULA states that I must make a spreadsheet:

LP earned for O-Plexing in Fronline Systems

So basically you're going to earn more LP per hour when risking a cheap fast aligning "you can't catch me noob" T1 frigate in all Small plexes except for NVY-1 than you will risking a destroyer or cruiser* in the considerably more dangerous "surprise mother fucker here's a Curse and a Huginn suddenly appearing" Large & Medium ADV-1.

FW is great but this really doesn't make sense to me. Can anyone make it make sense?

^\more dps than a cheap frig is required to break the rats in a time that doesn't completely kill your already lower LP/min.)