Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.
Using the power of the cloud, we monitor every realms Auction House, even when you're not in-game, and process this data through our custom system developed together with gold experts. We then serve this data directly to you through the Zygor Guides Client, allowing you to gain months of Auction House analysis in seconds. What this means is that our gold guide can dynamically adapt to the unique marketplace conditions of every realm you play on. Best of all, this service is included as part of Zygor's Gold and Auctions Guide.
You are right here. The Rematch string is part of the Info box, and as such it should be parsed correctly. (The string that contains the correct and breed/damage-specific min health requirements). This should be enough, but, I think there are also folks that aren’t using Rematch. They also should know of the type-specific min health requirements. Unfortunatly the default forms of the page don’t offer any detailed entries for the min health. They only offer one entry (for all damage types), and I always put the worst-case min health there (for pets that are weak against the expected damage type)