"For Mina in Star vs. the Forces of Evil, I wonder how long it would have taken to find other armor without Moon's help, since it can be recovered."
Analysis using canon from the Star vs. the Forces of Evil wiki and show details:
In Star vs. the Forces of Evil (SVTFOE), Mina Loveberry is an ancient Solarian Warrior, originally transformed by Queen Solaria Butterfly centuries ago using the Solarian Metamorphosis spell. This gives her superhuman strength, durability, and a "hulked-out" super-soldier form even without external gear.
The "armor" refers to the gigantic magical suits used by Solarian Warriors — massive, building-sized mechs with powerful energy swords that negate magic and cause lingering fatal wounds.
Canon evidence:
After Eclipsa's rise to power, Mina independently begins rebuilding the Solarian army. She collects remnants/scattered pieces of the old gigantic suits of armor from around Mewni (as stated directly on the Solarian Warriors page of the SVTFOE Fandom wiki).
She recruits dissatisfied Mewman peasants and has her crow Sebastian assemble/rebuild these suits.
Mina is shown actively gathering and scavenging these remnants on her own before approaching Moon.
Moon's help comes later: Moon performs (or assists with) the Solarian Metamorphosis spell to empower the new recruits into full Solarian Warriors and activates/enhances their powers and armor.
Without Moon's help (i.e., no new spell to empower additional warriors):
Mina could still recover and reuse the existing remnant armors herself, as she was already doing.
She would likely have a smaller force (perhaps just herself in a rebuilt suit, plus any old remnants she could salvage for limited use).
Time estimate: Canon shows Mina progressing quickly on her own (scavenging across Mewni). It might have taken her weeks to months to fully recover and assemble enough for a personal super-powered suit or a very small group, rather than the rapid large-scale army she builds with Moon's magical boost.
The armors are explicitly recoverable/reusable remnants from the ancient war, not destroyed permanently unless actively demolished in battle (e.g., by powerful spells like Eclipsa's).
In short, Mina was already on track to recover and use other/old armor independently — Moon's involvement accelerated the process and scaled it up massively by creating new warriors to pilot them.