メソッド名が動的←→静的と対称的であったりもしないし・・・

Cell: get, get_mut, set
RefCell: get_mut, borrow, borrow_mut

ただしget_mutはそれぞれ
https://doc.rust-lang.org/std/cell/struct.Cell.html#method.get_mut
> this method expects self to be mutable, which is generally not the case when using a Cell.
https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.get_mut
> this method expects self to be mutable, which is generally not the case when using a RefCell.
とあり通常の用途とやらで考えると

Cell: get, set
RefCell: borrow, borrow_mut

共に"Cell"で内部可変性を表現しつつ
用途はメソッド名で十分わかるしまぁもういいのかこれで