-Mods adding ships or weapons that are categorically better than the median make the game easier, because the player can prioritize them while AI autofits will only occasionally land on them.
-Mods adding ships or weapons that are categorically worse than the median make the game easier, because the player can neglect to ignore them while AI autofits will still take them.
-Mods adding ideally balanced ship ships or weapons make the game easier, because the player can utilize their specific strengths and weaknesses to yield a slightly more min-maxed ship, while autofits may or may not apply the new weapons very well.*
Conclusion: Any mod that adds any player-accessible content will result in an easier game.
Clearly what is needed is a mod that replaces existing ships and guns with Hounds and Thumpers.
I do find it interesting that the OP singles out the Pirates and Luddic Path, so let's focus on those for a second. Those specific factions don't get buffed because they're intended to be low-end, poorly funded, introductory threats; they're generally the first ships you ever fight. Neither of which are intended to be strong opposition forces, especially compared to vanilla organized factions. You can get under-moduled Orbital Stations as pirate bounties (2 modules of 3, used to be 1 module as recently as last update), and all the weak random bounties are pulled from random Pirates. Pirates have maybe 1 or 2 heavy industries and no nanoforge, and Pathers don't even have the Heavy Industry capacity.
Strictly speaking, it's perfectly possible to arbitrarily buff both of those factions, such as giving a Nanoforge planet to Pirates/Pathers, shoving in Pirate-y ships that are closer in power levels to Falcon (P)s than Wolf (P)s, and cranking their frequency way up, adding special elite skins of Pirates akin to the XIV Battlegroup**, but that's not usually done by faction packs or For one, it's outside the scope of most content packs unless it's a generic pack or a "buff pirates" sort of pack. For two, it's a general rule that you don't arbitrarily go against theme of any said faction when introducing new content: Dominant factions remain dominant, weak pirates remain weak, and Tri-Tachyon remains an avid user of all things high tech and Phase, unless changing the status quo is an explicit goal of the content pack.
I vaguely recall a mod originally billed as a Hullmod expansion pack, which also had an undocumented effect of buffing Remnants basically across the board. That'd make fighting Remnants more difficult naturally, but this was rather controversial because, among other things, the mod was never billed as a "change vanilla content" mod or a "make things harder" mod.
*IME while a generally well-balanced mod will necessarily yield slightly-more min-maxed ships (as otherwise it'd fall under "categorically worse than vanilla" content balance-wise), this has a trivial impact on game difficulty, if any. To me, the game becomes no more difficult if I uninstall all the mods and in some ways actually becomes easier (I haven't "memorized" to a practical effect all the weapons of my mods, which is not true for Vanilla ships and weapons).
**Yeah I know about the reAL DoMaIN stuff, but that's a meme so it doesn't count