When working with JSP tags on struts i can see that sometimes 2 diffrent tags with same type is called with the same instance.
Example:
JSP
<jcv:text id="email" maxlength="255" property="valueObject.Email"/>
<br>
<jcv:text id="phone" maxlength="255" property="valueObject.Phone"/>

TLD
<tag>
<name>text</name>
<tagclass>tti.jcore.views.form.tag.JViewsTextTag</tagclass>
...
</tag>

I can see that the public int doStartTag() called for both with the same instance.