Seems fine to me. Did we want to slot in "or X ratweres" at some point? An equivalent EL would be something close to 1d6 at level 8-9, then 2d6 and 3d6 subsequently.
Just to be clear.
The original of the Night Howler greater wererat could control normal "lesser wererats" (which became Ratweres in our conversion) once it reached high enough level.
The original version of the Wererat Lord could summon packs of rats, and the "clan leader" can control wererats it has created.
I'd be fine allowing the Greater Wererat to be able to summon Ratweres, but it's inappropriate for the Wererat Lord.
Come to think of it, neither of these creatures could summon lycanthropic minions as base monsters, but gained the ability at higher levels. That suggests we should do the same for our conversions.
Looking over the table in my previous post, I realize the level-equivalents are one too low - a 4-5 HD Wererat Lord is a 1st-2nd level character plus 3 HD of wererat. Secondly, I think the numbers could do with a little more tweaking.
How about the following:
Summon Ratkin (Su): Once per day, as a standard action, a greater wererat can call forth 1 rat swarm or a pack of 1d6+1 dire rats. These creatures arrive in 2d6 rounds and serve the wererat for up to 1 hour.
A greater wererat's summoning ability increases as it gains additional hit dice. It can summon larger numbers of rodents, and at 8 Hit Dice it gains the ability to summon ratweres. See the Greater Wererat Summoning Table for details.
A greater wererat can only use summon ratkin on ratweres it personally created by infecting a dire rat with ratwere plague. If no such ratweres exist, the greater wererat can only summon normal or dire rats.
Greater Wererat Summoning Table
|Hit Dice||Ratweres||Rat Swarms||Dire Rats|
Summon Ratkin (Su): Once per day, as a standard action, a wererat lord can call forth 1d2 rat swarms or a pack of 2d6 dire rats. These creatures arrive in 2d6 rounds and serve the wererat for up to 1 hour.
A wererat lord's summoning ability increases as it gains additional hit dice. It can summon larger numbers of rodents, and at 8 Hit Dice it gains the ability to summon wererats. See the Wererat Lord Summoning Table for details.
A wererat lord can only use summon ratkin on wererats it personally created with its curse of the ratlord ability. If no such wererats exist, the wererat lord can only summon normal or dire rats.
Wererat Lord Summoning Table
|Hit Dice||Wererats||Rat Swarms||Dire Rats|