This is hypothetical as we are not expecting #2 yet: What would you name [name_u]Florian[/name_u]'s little brother.
Bonus points for names of [name_m]German[/name_m], Polish or Slavic origins. Doesn’t need to be [name_m]Wolfgang[/name_m], [name_m]Bogdan[/name_m] or [name_m]Stanislaw[/name_m], though. 
[name_m]Ansel[/name_m] seems like a good fit.
Other suggestions:
[name_m]Casimir[/name_m]
[name_m]Ferdinand[/name_m]
[name_m]Alonso[/name_m]
[name_m]Kasper[/name_m]
[name_m]Walter[/name_m]
[name_m]Nicolai[/name_m]
[name_m]Ansel[/name_m] is a good suggestion! Or [name_m]Anselm[/name_m].
[name_u]Florian[/name_u] &
(Germanic origins)
Aidric
[name_m]Benno[/name_m]
[name_m]Bruno[/name_m]
[name_m]Conrad[/name_m]
[name_m]Emmerich[/name_m]
[name_m]Gunther[/name_m]
[name_m]Henrik[/name_m]
[name_m]Leonard[/name_m]
[name_m]Leopold[/name_m]
[name_m]Luther[/name_m]
[name_m]Otto[/name_m]
[name_m]Wolfgang[/name_m] (I know you said not such elaboratness, but i really like it!)
Wolfram
(Polish/Slavic)
Jaromir
[name_m]Zenon[/name_m]
(Others, unsure about all of their origins, but many, not all, have usage by [name_m]German[/name_m]/Slavic/Polish people)
[name_m]Albin[/name_m]
[name_m]Albus[/name_m]
[name_m]Edric[/name_m]
[name_m]Igor[/name_m]
[name_m]Isidore[/name_m]
[name_m]Justus[/name_m]
[name_m]Marcel[/name_m]/[name_m]Marcellus[/name_m]
[name_m]Oswald[/name_m]
[name_m]Oswin[/name_m]
[name_m]Rainier[/name_m]
[name_m]Valerian[/name_m]
[name_m]Valor[/name_m]
Some of these are maybe a little far out, but [name_u]Florian[/name_u] is a cool name and I feel like he needs an edgy brother! I particularly like [name_u]Florian[/name_u] and [name_m]Isidore[/name_m]! All the best :).
[name_m]Carlton[/name_m]
[name_m]Gunnar[/name_m]
[name_m]Gage[/name_m]
[name_m]Leander[/name_m] (pronounced lee-AN-der)
[name_m]Viggo[/name_m]
[name_u]Walker[/name_u]
[name_m]Milo[/name_m]
[name_m]Soren[/name_m]
[name_m]Stellan[/name_m]
[name_m]Ansel[/name_m], [name_m]Viggo[/name_m], [name_m]Justus[/name_m], [name_m]Isidore[/name_m], [name_m]Bruno[/name_m], [name_m]Conrad[/name_m] and [name_m]Otto[/name_m] are all great names. Thank you, so far.
Here are some names that I think would go well with [name_u]Florian[/name_u]… some may be a bit too out there for you though.
[name_m]Romulus[/name_m]
[name_m]Thierry[/name_m]
[name_m]Amaury[/name_m]
[name_m]Raphael[/name_m]
[name_m]Crispin[/name_m]
[name_u]Remy[/name_u]
[name_m]Cornelius[/name_m]
[name_m]Demetrius[/name_m]
[name_m]Horatio[/name_m]
[name_u]Adair[/name_u]
[name_u]Auberon[/name_u]/[name_u]Oberon[/name_u]
[name_u]Constantine[/name_u]
[name_m]Leander[/name_m]
[name_m]Evander[/name_m]
[name_u]Antoine[/name_u]
[name_m]Gaspard[/name_m]
[name_m]Geoffrey[/name_m]
[name_m]Emrys[/name_m]
[name_m]Idris[/name_m]
[name_m]Magnus[/name_m]
[name_m]Maxim[/name_m]
[name_m]Julius[/name_m]
[name_m]Ulysses[/name_m]
I actually have Polish great-uncles named [name_u]Florian[/name_u] and [name_m]Isidore[/name_m], so I agree that they go very well together!
Some other suggestions:
[name_m]Edmund[/name_m]
[name_m]Casper[/name_m]
[name_m]Henrik[/name_m]
[name_m]Josef[/name_m]
[name_m]Johan[/name_m]
[name_m]Victor[/name_m]
[name_m]Frederick[/name_m]
[name_m]Benedict[/name_m]
[name_m]Arthur[/name_m]
I adore the fact that you have a [name_u]Florian[/name_u]. I love this name so much!
[name_m]Amias[/name_m]
[name_m]Emil[/name_m]
[name_m]Emmerich[/name_m]
[name_m]Casimir[/name_m]
[name_m]Danilo[/name_m]
[name_m]Leopold[/name_m]
[name_m]Matthias[/name_m]
[name_m]Milos[/name_m]
[name_u]Nico[/name_u]/[name_u]Niko[/name_u]/[name_m]Nikos[/name_m]
[name_m]Nils[/name_m]
[name_u]Sascha[/name_u]
[name_u]Florian[/name_u] and [name_m]Julius[/name_m]
[name_m]Marius[/name_m] and [name_m]Hugo[/name_m] came to mind first.