Its probably not typical - but i do exactly that. I wanted to reuse my old 190w panels when i did my new system with 370w - so i put pairs of the old 190w panels into TIGO TS4 AO 450W units in parallel so that there AMPs were pretty close to max amps of the 370w - seems to work well and let me reuse 20 old panels and add them to then end of a couple of strings.
Its good for me as the roof where i wanted to put them get a lot of winter shade (only about 3 hours sun a day) so the TIGOs take them out of the array during winter and then in summer they produce nearly all day
Craig
