there was no limit in the number of packrats one could have, but they DID had one downfall flimsyness (they were easely killed, as their defence was only as good as normal rats)
Later on you got to buy transport-kodo's. They could carry 500-750 weight (thats more than your own carrying limit)
they were tough, yet slow, but they'd do.
Does oblivion have anything that looks like it? like for example having mules or packhorses that follow you?
Also : in morrowind one could hire "assistance" NPC-fighters that you'd hired to fight with you (you needed to pay their wages regulairly or they would leave)
you could use their inventory as "225 free storage space" as well. and you could equip them with armour, potions, and weapons (they would use whatever you gave them, since when you hired them they often had very crappy gear)
They'd level up, just like you, so whatever weapon you gave them, they grew stronger in.
-> it was for some even possible to learn them a few spells, on the condition you already knew them and their skill was high enough to use them.
Does Oblivion has anything like this? having a gang of fighters is just more fun than being alone:)