The same basic ideas apply, but since you've got older ddr2 I doubt it'll matter much. There were not as many banks and no bank groups back then, so dual-die setups might not even hurt performance much at all. It's been a long time since i've thought about ddr2. I guess you're ok, I wouldn't worry about it.
The biggest performance effects are likely to come from the actual speed of the memory sticks and the latencies your motherboard/laptop bios configure.
Matching Samsung 2Rx8 sticks should be fine, or just use the crucial you already have. I doubt you'll notice a difference. If this laptop supports dual channel memory, then having two identical/matching sodimms would be the best choice, regardless of make/model.
Sorry I had just assumed we were talking about recent ddr4.