My problem with this idea is that you can't cast spells in Wild Shape -- so you either have to make the ability a 'burn a spell slot to do this' thing like healing in Wild Shape, or you have to have the druid stay in non-animal form for one or more rounds to 'buff up' before actually getting to Wild Shape.
(I suppose a third option would be to specifically design the spells to have all-day durations, so the druid expends them at the start of the day and gets their benefit all day long, but that creates other issues, such as allowing more powerful buff spells but limiting them by use of the Concentration mechanic. Just saying that this issue is not necessarily a simple one, with the current design of the class. If the class had been solely designed as a shapeshifting class, there would be fewer of these kinds of issues, but it's too late to close the gate to the animal pen now.)
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Pauper