It seems I was right Animate Dead cannot be dispelled ( as I recall 1.14 was the last version in wich animated units could be dispelled). Animate dead is a super ultimate spell , but compared to Ressurection it has a small shortcoming, ressurection is better for the only reason that it provides hp in battle.
The type of units that are revived is not a problem because this game is very well balanced, it's impossible to get level 6 on a hero and your base and units as well as your oppnent's units to be tier 1.
Animate Dead has its advantages : for example you fight in open field with someone , u defeat him and he retreats with few hp in his fully towered base the animated units will finish the job because they are invulnerable, another advantage is that it animates enemy units too.The animated units are one certain damage machine, their invulnerable status makes them imune in front of any effect I mean for example if u have an animated rifleman you know for certain that he will provide continuus damage to your enemy no matter what for 40 seconds, the ressurected units are not spell free .