aww Meta 2 whole weeks!!! what am I gonna do at work without you there to pester me :( You better take care of yourself while you are away on the base. ok ;)

Anyway Amadin I'll try to explain what Meta said.

If you want to train with a pet and combo with it you need to have that pet fall within a -99 to +99 of your spd. For example say you have a character with 800 spd and you have a pet with 550 spd. Your character can combo with anyone in your team that falls within (800-99) 701 spd up to (800+99) 899 spd. Your pet can combo with anyone that is between (550-99)451 spd and (550+99)649 spd. So:
Character: 800 spd (combo range 701 - 899 spd)
Pet: 550 spd (combo range 451 - 649 spd)

In this scenario your characters spd doesn't fall with your pets combo range and your pets spd doesn't fall within your characters combo range. So if you were to train you could not combo.

2nd example:

Your character has 846 spd and your pet has 769 spd. Your character can combo with anyone with spd between (846-99) 747 spd and (846+99) 945 spd. Your pet can combo with anyone with a spd between (769-99) 670 spd and (769+99) 868 spd. So:

Character: 846 spd (combo range 747 - 945 spd)
Pet: 769 spd (Combo range 670 - 868 spd)

In this 2nd scenario your characters spd fall in your pets combo range and your pets spd falls within your characters combo range.

3rd example
Your character has 800 spd and your pet had 650 spd.

If you go back to the first example you should know that the combo range for 800 spd is 701 - 899 spd. Your pets combo range is (650-99) 551 spd and (650+99) 749 spd. So:

Character: 800 spd (Combo range 701 - 899 spd)
Pet: 650 spd (Combo range 551 - 749 spd)

With this information we can see that your character and pet could not combo together if they trained alone. But if you happened to have an alt you could make them combo. If your alt happened to have 723 spd then his combo range would be (723-99) 624 spd up to (723+99) 822 spd

Character: 800 spd (Combo range 701 - 899 spd)
Alt: 723 spd (Combo range 624 - 822 spd)
Pet: 650 spd (Combo range 551 - 749 spd)

While your characters spd doesn't fall in your pets combo range and your pets spd doens't fall within your characters combo range the spd of your alt falls within both. So your alt with 723 spd could combo with your character if they were along and with your pet if they were alone. If you put them in a team together and had them train your pet would combo with your alt because the pet falls within the alts combo range and the alt would combo with your character because he falls within your characters combo range.

Because your pet is already comboing with your alt and your alt is going to combo with your character then end up attacking at the same time. Many people call this "stacking" (or atleast most of the people I know call it this :P lol) "Stacking" is where you take characters and pets and manipulate their spd so that 1 character or pets spd is within the combo range of another pet and that character or pet's spd is within another character or pet's combo range while the 1st one might be ouside of the combo range. You keep doing this and "stack" the character's/pet's spd until they all fall within each others combo ranges like in example 3.

When you can accomplish this you can combo with a full team even when their spds are like mets character's and pet's. His team has a pet with 199 spd and yet it can combo with another pet with 425 spd because his other characters and pets within the team have spds that fall within each others combo ranges. So the spds are "stacked" to allow all of his characters to combo.

Well....I'm tired :P and I'm sure this is probably REALLY long lol I hope I managed to explain what Meta said a little better. When you want to manipulate your spd and the spd of your pets to get them in the combo ranges just use -spd equips and +spd equips. I hope this helps you even a little bit. ^^ good luck training :D