Must the subnet be the same for all of them? My interfaces have several IPv6 addresses.
GW2 has a 64-bit client and appears to be trying desperately to get rid of the 32-bit client. SWTOR has only a 32-bit client, and the history of the game's development basically makes a 64-bit client project a non-starter. I'm also mildly intrigued by the contrast with SWTOR. (And laptops, historically, have been built for longer battery life and lower weight rather than higher performance.) The bigger the game state (because of client bitness, say), the more the memory frequency will bite you. There isn't enough cache in the CPU for all of a game's state, so the CPU must go back and forth to memory for it, and if the memory frequency is slow, that will wreck performance.
That sort of consideration is why memory frequency is an important parameter in the construction of gaming rigs. Like the main memory cache, the TLB is of limited size, and the more pages you touch, the more TLB entries you need, and the more likely you are to not have enough room for them. You can also end up facing another caching limit called TLB misses, where the CPU has to keep fetching page table entries from memory rather than from the "Translation Lookaside Buffer". Instructions and data take longer to load because there are more cache misses, therefore the CPU gets less done in the same amount of time and/or takes longer to do the same things. Task Manager as if it is a CPU-usage increase.
Given that the 64-bit client must use more memory, it will, for example, have to load more data from memory, and although the performance bottleneck is in fact a memory bandwidth limit, it will show up in e.g. OP didn't say how big the memory in the laptop is, but he did say that the laptop sucks. If I missed it somewhere, though, I'm sorry.