[name_m]Hi[/name_m] there.
[name_m]Larry[/name_m] for a lovable mutt is so cute. I think that [name_u]Beau[/name_u] would be very nice for a brother.
Here are my thoughts on the rest of your list-
Lennon-Meh, it’s okay. I love [name_u]John[/name_u] Lennon; but I don’t like [name_m]Lenin[/name_m]. And I just don’t think that this sounds that pretty.
Leroy-That’s fun, but too close to [name_m]Larry[/name_m].
Leopold-Leo is adorable, but kind of close to [name_f]Leelee[/name_f] for sure.
Ethel-That’d be amazing for a dog.
Selenas-I’m not familiar w/this name. Not sure how I feel about it.
Jillian-Not my cup of tea. Feels a bit meh.
Thelma-Not my style, but could not be more perfect w/Larry.
Gertrude-I’d die happy if I met a dog named [name_f]Gerty[/name_f].
Agnes-That’s pretty cute. I know a beautiful cat named this, & love it on her.
Matilda-Yeah, I feel like it doesn’t fit w/Larry & it’s just a little done. Mostly just on these boards, so maybe in real life it feels more interesting. But [name_f]Tilly[/name_f] seems hard to avoid.
Walter-That’s really charming. I met a [name_m]Basset[/name_m] Hound named this before. So stinkin’ cute!
Jimothy-Meh, I don’t know. Seems a tad made-up-ish.
Chester-I want to like this name. I really like [name_m]Chet[/name_m]. [name_m]Chester[/name_m] just sounds weaselly to me.
Gilbert-This has a similar vibe as [name_m]Chester[/name_m], but sweeter. I can totally see this on a dopey lovable pup.
Hal-I like that too. Better as a nn for maybe [name_m]Harold[/name_m]? [name_u]Or[/name_u] is that too close to [name_m]Larry[/name_m]?
A few more ideas-
Girls-
[name_f]Audrey[/name_f]
Bea(atrice)
[name_f]Dorothy[/name_f]
[name_f]Edith[/name_f]
[name_f]Fern[/name_f]
[name_f]Frances[/name_f]
[name_f]Gloria[/name_f]
[name_u]June[/name_u]
Susan/Susie
[name_f]Tess[/name_f]
[name_f]Wilma[/name_f]
Boys-
[name_u]Alfie[/name_u]
[name_m]Albert[/name_m]
[name_m]Bernard[/name_m]
[name_m]Barney[/name_m]
[name_u]George[/name_u]
[name_m]Ned[/name_m] (Edward nn Ned?)
[name_m]Winston[/name_m]
[name_f]Hope[/name_f] this helps.