Rumors for the series suggest that it might have some folk tale elements as the rumored Red Hero is based on Momotaro. The brothers on the name might suggest that it will be a team of siblings or at least, considers themselves as siblings.
[via Tokusatsu Network]
*Toei confirmed in official sources that Lupinranger is the 42nd Super Sentai team and Patranger is the 43rd Super Sentai team. Lupinranger vs. Patranger is the 42nd Super Sentai TV series. But around Zenkaiger, Toei lumped Lupinranger and Patranger in the same 42 numbering even though they still consider the two as two separate teams.