Cleansing or roll dodging out of bombard's root doesn't grant root immunity, allowing someone to be re-snared every few seconds without root immunity-granting abilities/potions.
Only sitting for the full 4 second root duration grants 5 second root immunity, besides running shuffle / race against time / immovability pots.
While shuffle and race against time are efficient counters - re-casting them and wasting 1 gcd every 2-5 seconds is a strong resource drain. Additionally, not everyone runs shuffle or race against time.
Suggestion: lower Bombard's root/movement speed reduction timer to 1.5 seconds, letting it retain its function as a root but without its current oppressive nature (especially in BGs).