Only do that if you want to have something like 2 (or more) different strategies in the same EA. Like 2-in-1. But remember that it is still one EA and if the strategies are completely different, it's better to just make two separate EAs.
Otherwise... imagine that you have 2 different groups of blocks that are separate - one for the first strategy and one for the second. In all blocks in the second groups of blocks where you have Group, you should set it to 2 for example. Such blocks are "No trade", "Buy now" and basically all these blocks who are working with trades or pending orders.
The EA will have one master magic number (it's the MagicStart parameter of the EA) and where you have Group number that is different than 0 (empty value), the magic number will equal to MagicStart + Group.
