Spells?

[ConjurerDragon]

I don´t understand that entry in spells.xml:

<item>
<f_power>12.00000000</f_power>
<i_dlcId>0</i_dlcId>
<i_stage>1</i_stage>
<i_researchCost>25</i_researchCost>
<i_manaCost>23</i_manaCost>
<i_castTime10>8</i_castTime10>
<s_god/>
<i_godReputation>0</i_godReputation>
<b_isPerk>false</b_isPerk>
<b_isUnique>false</b_isUnique>
<action>
<s_effect>LifeMagic</s_effect>
<s_actionType>heal_buff</s_actionType>
<s_buff/>
<s_aoeType>aoe_1</s_aoeType>
<s_effectMainFilter>friendly</s_effectMainFilter>
<s_effectSubFilter>living</s_effectSubFilter>
<s_combo/>
<i_pollution>20</i_pollution>
<s_actionName>sp_arc_heal</s_actionName>
<s_targetMainFilter>friendly</s_targetMainFilter>
<s_targetSubFilter>living</s_targetSubFilter>
<i_range>0</i_range>
<f_multiplier>1.00000000</f_multiplier>
<i_cooldown>1</i_cooldown>
<s_terraforming/>
<effectLandFilter>
<i_positive>0</i_positive>
<i_negative>0</i_negative>
</effectLandFilter>
<targetLandFilter>
<i_positive>0</i_positive>
<i_negative>0</i_negative>
</targetLandFilter>
</action>
<chain/>
<researchPrereqs>
<s_Item>sp_arc_lesser_heal</s_Item>
</researchPrereqs>
<leadsTo/>
</item>

The last part "researchPreqs" sounds like you need to have researched "lesser heal" (the spell that heals 4 points) before you can research "heal" (the spell that heals 12 points). However in several games I have had Heal in the 5star research wheel before I got Lesser Heal...?

Edit: Screenshot of the research wheel with both lesser healing and healing available for research