Silverback vs. Spiked Collar

I did some more calculations for Silverback versus Spiked collar because it has been bothering me, could someone see if I made any glaring errors here?

My calculations are as follows-

The first bit is easy because SB gives 1.43 TPS per 1k health per point (10 health per 3.5 seconds*0.5 threat per point healed.)
or
0.013 threat per second per point of stamina per point.

30k pet health yields ~85 TPS and 50K yields ~144TPS. (Roughly)
*Edit* I forgot the healing modifiers, that should be 127.5 and 216 TPS respectively.

As far as I am aware overhealing does not generate threat, so the SB threat is only applied when the pet is not at full health.

Now for Spiked Collar it is more difficult because it does not look like the TS tooltip reflects the adjusted values for the damage per spell power point (and hence RAP point), so it is difficult to get a good estimate of the TPS generated by it.

It looks like the TS threat multiplier is 3, so every 1 damage generates 3 Threat.
That means if I increase the damage dealt by TS by 3% I should be increasing the threat generated by 9%.
In my tanking gear I am sitting on roughly 4k AP and TS seems to hit somewhere around 400 on average (slightly less if anything).
So taking 1 point SC will yield roughly ~40 additional damage or 120 threat translating to 17 TPS.

TS can also crit for what looks like double damage (I thought it was 1.5), giving 34 TPS, this is harder to model correctly because we do not know the pet crit rate exactly and CS plays a big role too, as far a I can tell it should not be nearly enough to overcome the deficit because even if you crit 100% of the time with TS, you still have a ~50TPS deficit to overcome.

SC will also give a bigger burst threat with BW+KC up, but even then the TPS deficit is not overcome if SB gives full threat which is more than than likely in that scenario anyway.

All in all it seems to me that the points are better spent in SB.

This matches some of the testing I did ages ago but I still find it surprising. Can you guys see anything obviously wrong here?

I'm not going to pretend to know a definitive answer to this question, but if you're just talking from a purely TPS standpoint, then there are situations where Spiked Collar could be more TPS than Silverback in practice even if its less in theory.

If your pet is either taking very little damage or being healed by multiple players, therefore leading to it having full heath a great deal of the time. Since as you mentioned overhealing doesn't cause threat, SB could end up both being less TPS and also the TPS would be less consistent.

Of course, Silverback's healing itself is certainly a big advantage over SC, so personally I change which one I use based on individual situations.

Bit of a fly in the ointment here, healing aggro is divided evenly amongst mobs rather than applied wholesale. So while the TPS boost for a single target holds, it does not really help so much for multiple targets.

So Spiked Collar is the better choice most likely.

The other thing is that Durante has now confirmed that the coefficient on TS is in fact 2.5 rather than the three I had in my original calculations (it was a rough figure so I might have rounded it).

I think that means that the AoE threat from Silverback will be better (if you are not overhealing) if you have less than 6 or so mobs on you. To account for overhealing, call it 4 I suppose.