Maybe it's just me, but putting Thanos is a little dubious? I know Infinity War is billed as an Avengers movie, but Thanos does have significantly more screen time than anyone else.
The 2003 one with Eric Bana isn't. The 2008 one with Ed Norton is. It's actually the second film of the MCU, after Iron Man released earlier the same year. Mark Ruffalo took over for Ed Norton in the first Avengers movie in 2012.
Hate having Star Lord as a choice. At a minimum the first Guardians was his origin story and it wasn't until 3 that I'd call it a full Guardians movie. If the first one would have been called Guardians of the Galaxy: Star Lord and nothing else changed would it be a solo movie?