Well actually the Touhous imitated Nanoha's first.
Touhou predates Nanoha by a good five years. Counting from the latter's first appearance AS a magical girl (instead of the background imouto character) in Triangle Heart 3: Lyrical Toy Box.
Touhou predates Nanoha by a good five years. Counting from the latter's first appearance AS a magical girl (instead of the background imouto character) in Triangle Heart 3: Lyrical Toy Box.
You can't really count the PC-98 stuff, that's a separate canon and didn't spawn these memes. The current generation that resulted in mass popularity and spawned the meme only began in 2002 with Embodiment of Scarlet Devil, still slightly older, but it didn't just drop and then have thousands of fanworks and take over the world instantly when it did, even more so in the west. Neither I or anyone else I knew into Japanese nerd culture really knew of Touhou in 2004 when Nanoha aired, but the 'befriended' meme began almost immediately within the fandom regardless.
Touhou started to become the Juggernaut it was later, toward the end of the decade (I know it's hard to fathom a time before Touhou was this monstrous thing every otaku on the interwebs knew about for those of about drinking age or less, but such a time did exist). At least in my experience in the west the "Friendship through superior firepower" meme definitely does seems to have first become widespread in the Nanoha fandom before Touhou was much of a 'thing'.
If Nanoha didn't invent it and then have it cross pollinate to the current Touhou fanon during it's very early days I'd argue it might well have been independent convergent evolution.
Edit: Also talking about shit that happened in fandom cultures ten years ago has suddenly made me feel old as shit.
You know, that does explain why it feels so familiar when I watch little miss Mike doing her things on the Harekaze. She's secretly a student of the Takamachi School of Befriending, isn't she?